This ppt is made from the bio-inorganic point of view for those who are having difficulty in finding the correct type and quality of information. This ppt has all the important points which one needs to know about this topic.
This document summarizes key aspects of hemoglobin structure and function. It discusses how hemoglobin is a tetrameric protein with two alpha and two beta subunits that each bind one heme group. Hemoglobin exists in two conformational states - relaxed (R) state when oxygen is bound and tense (T) state when oxygen is not bound. Binding of oxygen causes a transition from the T state to the R state. This allosteric transition allows hemoglobin to efficiently bind and release oxygen in the lungs and tissues. The document also describes how hemoglobin transports hydrogen ions and carbon dioxide in the blood and how its oxygen binding is regulated.
This document compares and contrasts the proteins hemoglobin and myoglobin. It discusses their structures, functions, and key differences. Hemoglobin is an oxygen transport protein found in blood consisting of four subunits, while myoglobin is an oxygen storage protein located in muscle tissue. Both contain a heme group that binds oxygen, but hemoglobin can bind four oxygen molecules total due to having four subunits, each with their own heme group. Myoglobin only has one subunit and heme group and thus can only bind one oxygen molecule. The document also covers cooperativity in hemoglobin and how oxygen binding causes a conformational change in its structure.
Myoglobin is a protein found in muscle tissue that binds oxygen. It was the first protein whose three-dimensional structure was determined using X-ray crystallography in the 1950s-60s. Myoglobin facilitates oxygen transport within muscles through reversible binding of oxygen to an iron-containing heme group. It stores oxygen to help meet rapid energy demands in muscle cells and prevents accumulation of toxic nitric oxide.
INTRODUCTION
DISCOVREY OF MYOGLOBIN STRUCTURE
STRUCTURE OF MYOGLOBIN
APOMYOGLOBIN
MECHANISM-
BINDING OF OXYGEN TO MYGLOBIN
DISASSOCIATION OF OXYGEN FOROM MYOGLOBIN
IMPORTANT FEATURES OF MYOGLOBIN
BIOLOGICAL SIGNIFICANCES OF MYOGLOBIN
CONCLUSION
REFERENCES
This document summarizes key information about hemoglobin and myoglobin. It discusses how hemoglobin and myoglobin were the first proteins to be crystallized and have their structures determined via X-ray crystallography. The document describes the structures of myoglobin and hemoglobin, including their subunit composition and heme groups. It explains how oxygen binding causes conformational changes in hemoglobin that result in cooperative binding and the release of oxygen in tissues.
This document provides an introduction to hemoglobin and myoglobin, including their structures, functions, and a comparison between the two. Hemoglobin is an oxygen-transport protein found in red blood cells that binds to oxygen in the lungs and delivers it to tissues throughout the body. Myoglobin is an oxygen-storage protein found in muscle tissue that stores oxygen for use within muscles. Both proteins use a heme group containing iron to reversibly bind oxygen, but hemoglobin is a heterotetramer made of two alpha and two beta chains, while myoglobin is a monomer. The document also discusses cooperative binding in hemoglobin and allosteric regulation.
This document discusses the allosteric property of hemoglobin. It explains that hemoglobin exhibits homotropic and heterotropic effects that allow for efficient oxygen transport. The binding of oxygen to one subunit of hemoglobin facilitates the binding of oxygen to the remaining subunits, demonstrating positive cooperativity. Additionally, the affinity of hemoglobin for oxygen decreases in response to increases in hydrogen ions and carbon dioxide, allowing for effective oxygen unloading in tissues.
This document summarizes key aspects of hemoglobin structure and function. It discusses how hemoglobin is a tetrameric protein with two alpha and two beta subunits that each bind one heme group. Hemoglobin exists in two conformational states - relaxed (R) state when oxygen is bound and tense (T) state when oxygen is not bound. Binding of oxygen causes a transition from the T state to the R state. This allosteric transition allows hemoglobin to efficiently bind and release oxygen in the lungs and tissues. The document also describes how hemoglobin transports hydrogen ions and carbon dioxide in the blood and how its oxygen binding is regulated.
This document compares and contrasts the proteins hemoglobin and myoglobin. It discusses their structures, functions, and key differences. Hemoglobin is an oxygen transport protein found in blood consisting of four subunits, while myoglobin is an oxygen storage protein located in muscle tissue. Both contain a heme group that binds oxygen, but hemoglobin can bind four oxygen molecules total due to having four subunits, each with their own heme group. Myoglobin only has one subunit and heme group and thus can only bind one oxygen molecule. The document also covers cooperativity in hemoglobin and how oxygen binding causes a conformational change in its structure.
Myoglobin is a protein found in muscle tissue that binds oxygen. It was the first protein whose three-dimensional structure was determined using X-ray crystallography in the 1950s-60s. Myoglobin facilitates oxygen transport within muscles through reversible binding of oxygen to an iron-containing heme group. It stores oxygen to help meet rapid energy demands in muscle cells and prevents accumulation of toxic nitric oxide.
INTRODUCTION
DISCOVREY OF MYOGLOBIN STRUCTURE
STRUCTURE OF MYOGLOBIN
APOMYOGLOBIN
MECHANISM-
BINDING OF OXYGEN TO MYGLOBIN
DISASSOCIATION OF OXYGEN FOROM MYOGLOBIN
IMPORTANT FEATURES OF MYOGLOBIN
BIOLOGICAL SIGNIFICANCES OF MYOGLOBIN
CONCLUSION
REFERENCES
This document summarizes key information about hemoglobin and myoglobin. It discusses how hemoglobin and myoglobin were the first proteins to be crystallized and have their structures determined via X-ray crystallography. The document describes the structures of myoglobin and hemoglobin, including their subunit composition and heme groups. It explains how oxygen binding causes conformational changes in hemoglobin that result in cooperative binding and the release of oxygen in tissues.
This document provides an introduction to hemoglobin and myoglobin, including their structures, functions, and a comparison between the two. Hemoglobin is an oxygen-transport protein found in red blood cells that binds to oxygen in the lungs and delivers it to tissues throughout the body. Myoglobin is an oxygen-storage protein found in muscle tissue that stores oxygen for use within muscles. Both proteins use a heme group containing iron to reversibly bind oxygen, but hemoglobin is a heterotetramer made of two alpha and two beta chains, while myoglobin is a monomer. The document also discusses cooperative binding in hemoglobin and allosteric regulation.
This document discusses the allosteric property of hemoglobin. It explains that hemoglobin exhibits homotropic and heterotropic effects that allow for efficient oxygen transport. The binding of oxygen to one subunit of hemoglobin facilitates the binding of oxygen to the remaining subunits, demonstrating positive cooperativity. Additionally, the affinity of hemoglobin for oxygen decreases in response to increases in hydrogen ions and carbon dioxide, allowing for effective oxygen unloading in tissues.
A comprehensive presentation on Hemoglobin chemistry for medical ,dental ,biotechnology ,Life sciences ,& pharmacology students. Presentation includes structure & functions of a normal hemoglobin molecule.Bohr's effect along with allosteric modulators of hemoglobin for oxygen transport are illustrated.Molecular changes ,types,diagnosis, Management & inheritance of Sickle cell anemia is described .Types , mutations involved ,diagnosis ,inhertance & Management of Thalassemia disease is presented here . Presentation also involves other hemoglobinopathies Hb C/D/E /Lepore/Wyane etc.Changes in oxygen carrying capacity of hemoglobin after formation of Carboxy Hemoglobin is illustrated . Formation of Meth-Hb in vivo & in vitro is described along with its genetic & diagnostic aspects.Unstable variants & chronic Heinz body anemia are described briefly .Text is supported by Google images.
The document summarizes the structure and function of hemoglobin. Hemoglobin is a protein in red blood cells that carries oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs. It is composed of heme and globin proteins. Heme contains iron and is produced in mitochondria, while globin chains are produced by ribosomes and combine with heme to form hemoglobin. The main types of hemoglobin in humans are fetal hemoglobin during development and adult hemoglobin after birth. Hemoglobin transports oxygen via an oxygen-binding reaction that allows it to efficiently deliver oxygen to tissues and receive carbon dioxide.
This document summarizes key information about heme chemistry and hemoglobin. It discusses the structure and function of hemoglobin, including its role in oxygen transport and delivery to tissues. Hemoglobin is a protein composed of globin and heme groups that allows for the reversible binding and transport of oxygen in the blood. Factors like pH, carbon dioxide levels, and cooperativity between heme groups influence the oxygen binding affinity of hemoglobin.
Oxygen Binding by Myoglobin and HemoglobinAlecks Madrona
Oxygen binding proteins myoglobin and hemoglobin transport and store oxygen in the body. Myoglobin is a monomer that binds one oxygen molecule to carry oxygen to mitochondria in cells. Hemoglobin is a tetramer made of two alpha and two beta chains that binds four oxygen molecules cooperatively to carry oxygen from lungs to tissues. The heme group contains iron that binds oxygen. Hemoglobin exhibits positive cooperativity where binding of oxygen to one subunit increases the affinity of the other subunits. The Monod-Wyman-Changeux and Koshland models describe the transition between tense and relaxed hemoglobin states during cooperativity. 2,3-bisphosphoglycerate binds preferentially to deoxygenated hemoglobin and shifts
This document provides information on hemoglobin, including its structure, function, and role in oxygen transport. Key points include:
- Hemoglobin is an iron-containing protein in red blood cells that carries oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs.
- It consists of a protein component called globin and a non-protein component called heme, which contains iron.
- Hemoglobin has a tetrameric structure composed of two alpha and two beta subunits, each containing a heme group that reversibly binds oxygen.
- The binding of oxygen to one subunit influences the binding of oxygen to other subunits, allowing hemoglobin to load and unload oxygen cooperatively in response to changes in oxygen
Carboxypeptidase A is a digestive enzyme that hydrolyzes the carboxyterminal peptide bond in polypeptide chains. It uses an induced fit mechanism where substrate binding causes large alterations in the active site structure. The enzyme contains a zinc atom and other groups at the active site that induce electronic rearrangement, making the substrate more susceptible to hydrolysis. The zinc ion is coordinated in a tetrahedral array and the carboxyl oxygen of the peptide bond to be cleaved also coordinates with the zinc ion.
Hemoglobin and myoglobin are oxygen-carrying proteins in the blood. Hemoglobin is a tetrameric protein composed of four polypeptide chains that carry oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs. Myoglobin is a single-chain protein that stores oxygen in muscle tissues. Both proteins use heme groups containing iron to reversibly bind oxygen. The binding of oxygen is influenced by factors like pH, carbon dioxide levels, and 2,3-bisphosphoglycerate to facilitate oxygen delivery to tissues and carbon dioxide removal from tissues.
1) Iron is an essential trace element that is stored and transported throughout the body by heme-containing and non-heme proteins.
2) Ferritin and hemosiderin are the primary proteins involved in iron storage in the liver, bone marrow, and spleen. Ferritin stores iron in a soluble form while hemosiderin stores excess iron in an insoluble aggregate.
3) Transferrin is the main protein responsible for transporting iron through the blood plasma. It binds iron released from ferritin and transports it to tissues where iron is utilized or stored.
Hemoglobin is an oxygen-binding protein in red blood cells. It is composed of four polypeptide subunits - two alpha chains and two beta chains - as well as a heme group containing iron. The heme group gives hemoglobin its red color and allows it to carry oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs. Mutations in hemoglobin genes can lead to hemoglobinopathies like thalassemias, sickle cell anemia, and hemoglobin M disease. These disorders disrupt hemoglobin's ability to carry oxygen and can cause anemia.
1) Porphyrins are biomarkers that can identify toxicity to the heme biosynthesis pathway. Disturbances can cause accumulations of porphyrin intermediates in urine.
2) Testing porphyrin levels can identify biochemical damage from toxic exposures like mercury and monitor chelation therapy. Abnormal levels also correlate with conditions like chemical sensitivities and neurological disorders.
3) Case studies show porphyrin testing identified arsenic exposure from an elevated ratio and confirmed mercury toxicity in an autistic child with challenges excreting heavy metals.
Hemoglobin is a protein in red blood cells that transports oxygen throughout the body. It is composed of four polypeptide subunits, each containing an iron-containing heme group that reversibly binds oxygen. The subunits are made of two alpha and two beta chains. Hemoglobin transports oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs for exhalation. Erythropoietin is a hormone that regulates red blood cell production and hemoglobin synthesis, and its release is stimulated by low oxygen levels in order to increase oxygen delivery capacity to tissues.
1) Bioenergetics examines the energy flow in living organisms using concepts like entropy, enthalpy, and free energy.
2) ATP acts as the energy currency of cells, being produced through exergonic reactions and consumed to power endergonic reactions.
3) Standard free energy changes can be added for coupled reactions and actual free energy depends on reactant and product concentrations, driving reactions towards or away from equilibrium.
Heme Structure. synthesis and porphyrias Ravi Kiran
This document discusses the structure of hemoglobin. It begins by stating that hemoglobin is a globular protein in red blood cells with a normal level of 14-16 g/dL in males and 13-15 g/dL in females. Hemoglobin is made up of four subunits, with each subunit containing one heme group and one globin polypeptide chain. The four subunits can either be two alpha and two beta chains (HbA), two alpha and two gamma chains (HbF), or two alpha and two delta chains (HbA2). The document then describes the structure of heme and how it attaches to the globin chain in each subunit to form hemoglobin.
The document discusses the structure of proteins at various levels of organization:
- Proteins are composed of amino acids linked together by peptide bonds to form polypeptide chains. The sequence and interactions of these chains determine the protein's structure.
- There are four levels of protein structure - primary, secondary, tertiary, and quaternary. Secondary structure includes alpha helices and beta sheets formed by hydrogen bonding between amino acids in the chain. Tertiary structure describes the overall 3D shape formed by interactions between amino acid side chains. Quaternary structure involves the interaction of multiple polypeptide chains.
- Protein structure enables proteins to perform their diverse functions through processes like enzyme catalysis, oxygen transport, and providing structure
the ionophores are the a part of membrane transport system. these slides include general concept of ionophores. useful for the paramedical, medical students.
ATP is the most important form of chemical energy in cells. It is a nucleoside triphosphate containing adenine, ribose, and three phosphate groups. ATP is considered the universal energy currency of cells because it can easily donate a single phosphate, two phosphates, or its entire adenosine group to drive various energy-requiring cellular reactions and processes. ATP is regenerated through substrate-level phosphorylation during glycolysis and the citric acid cycle, as well as oxidative phosphorylation in the mitochondria. When ATP is hydrolyzed, energy is released to power cellular work.
This document summarizes the four levels of protein structure: primary, secondary, tertiary, and quaternary. It provides details on each level: primary structure refers to the linear sequence of amino acids in the polypeptide chain. Secondary structure involves hydrogen bonding between amino acids to form regular structures like alpha helices and beta pleated sheets. Tertiary structure describes the overall 3D shape of the protein arising from secondary structures. Quaternary structure involves interactions between two or more polypeptide chains, as seen in hemoglobin which is made of four polypeptide subunits.
Haemoglobin is a protein in red blood cells that transports oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs. It is composed of haem and globin subunits. Globin is produced in polyribosomes while haem is produced in mitochondria and the two subunits combine to form functional haemoglobin. Abnormalities in haemoglobin structure or levels can impair oxygen delivery and cause anemia.
Protein ligand interaction by KK Sahu sirKAUSHAL SAHU
The document discusses protein-ligand interactions, providing examples of hemoglobin and antibodies. It explains that proteins interact specifically with ligands through binding sites, and this interaction is important for functions like oxygen transport and immune response. Hemoglobin transports oxygen through a cooperative binding process where the binding of oxygen to one subunit affects the affinity of nearby subunits. Antibodies also bind specifically to antigens through complementary interaction, which is vital for the immune system. The reversible and specific nature of protein-ligand binding allows for important biological processes and applications.
This document provides an overview of globular proteins, with a focus on hemoglobin and myoglobin. It discusses the following key points:
- Globular proteins have hydrophilic amino acids on the outside and hydrophobic amino acids on the inside, allowing them to be soluble in water. Hemoglobin and myoglobin are important globular proteins.
- Hemoglobin transports oxygen in red blood cells, while myoglobin stores and transports oxygen in muscle cells. Both contain a heme group that reversibly binds oxygen.
- The structures of myoglobin and each subunit of hemoglobin involve alpha helices that form a pocket holding the heme group. Histidine residues help bind the heme iron and oxygen.
- Hemoglobin
A comprehensive presentation on Hemoglobin chemistry for medical ,dental ,biotechnology ,Life sciences ,& pharmacology students. Presentation includes structure & functions of a normal hemoglobin molecule.Bohr's effect along with allosteric modulators of hemoglobin for oxygen transport are illustrated.Molecular changes ,types,diagnosis, Management & inheritance of Sickle cell anemia is described .Types , mutations involved ,diagnosis ,inhertance & Management of Thalassemia disease is presented here . Presentation also involves other hemoglobinopathies Hb C/D/E /Lepore/Wyane etc.Changes in oxygen carrying capacity of hemoglobin after formation of Carboxy Hemoglobin is illustrated . Formation of Meth-Hb in vivo & in vitro is described along with its genetic & diagnostic aspects.Unstable variants & chronic Heinz body anemia are described briefly .Text is supported by Google images.
The document summarizes the structure and function of hemoglobin. Hemoglobin is a protein in red blood cells that carries oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs. It is composed of heme and globin proteins. Heme contains iron and is produced in mitochondria, while globin chains are produced by ribosomes and combine with heme to form hemoglobin. The main types of hemoglobin in humans are fetal hemoglobin during development and adult hemoglobin after birth. Hemoglobin transports oxygen via an oxygen-binding reaction that allows it to efficiently deliver oxygen to tissues and receive carbon dioxide.
This document summarizes key information about heme chemistry and hemoglobin. It discusses the structure and function of hemoglobin, including its role in oxygen transport and delivery to tissues. Hemoglobin is a protein composed of globin and heme groups that allows for the reversible binding and transport of oxygen in the blood. Factors like pH, carbon dioxide levels, and cooperativity between heme groups influence the oxygen binding affinity of hemoglobin.
Oxygen Binding by Myoglobin and HemoglobinAlecks Madrona
Oxygen binding proteins myoglobin and hemoglobin transport and store oxygen in the body. Myoglobin is a monomer that binds one oxygen molecule to carry oxygen to mitochondria in cells. Hemoglobin is a tetramer made of two alpha and two beta chains that binds four oxygen molecules cooperatively to carry oxygen from lungs to tissues. The heme group contains iron that binds oxygen. Hemoglobin exhibits positive cooperativity where binding of oxygen to one subunit increases the affinity of the other subunits. The Monod-Wyman-Changeux and Koshland models describe the transition between tense and relaxed hemoglobin states during cooperativity. 2,3-bisphosphoglycerate binds preferentially to deoxygenated hemoglobin and shifts
This document provides information on hemoglobin, including its structure, function, and role in oxygen transport. Key points include:
- Hemoglobin is an iron-containing protein in red blood cells that carries oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs.
- It consists of a protein component called globin and a non-protein component called heme, which contains iron.
- Hemoglobin has a tetrameric structure composed of two alpha and two beta subunits, each containing a heme group that reversibly binds oxygen.
- The binding of oxygen to one subunit influences the binding of oxygen to other subunits, allowing hemoglobin to load and unload oxygen cooperatively in response to changes in oxygen
Carboxypeptidase A is a digestive enzyme that hydrolyzes the carboxyterminal peptide bond in polypeptide chains. It uses an induced fit mechanism where substrate binding causes large alterations in the active site structure. The enzyme contains a zinc atom and other groups at the active site that induce electronic rearrangement, making the substrate more susceptible to hydrolysis. The zinc ion is coordinated in a tetrahedral array and the carboxyl oxygen of the peptide bond to be cleaved also coordinates with the zinc ion.
Hemoglobin and myoglobin are oxygen-carrying proteins in the blood. Hemoglobin is a tetrameric protein composed of four polypeptide chains that carry oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs. Myoglobin is a single-chain protein that stores oxygen in muscle tissues. Both proteins use heme groups containing iron to reversibly bind oxygen. The binding of oxygen is influenced by factors like pH, carbon dioxide levels, and 2,3-bisphosphoglycerate to facilitate oxygen delivery to tissues and carbon dioxide removal from tissues.
1) Iron is an essential trace element that is stored and transported throughout the body by heme-containing and non-heme proteins.
2) Ferritin and hemosiderin are the primary proteins involved in iron storage in the liver, bone marrow, and spleen. Ferritin stores iron in a soluble form while hemosiderin stores excess iron in an insoluble aggregate.
3) Transferrin is the main protein responsible for transporting iron through the blood plasma. It binds iron released from ferritin and transports it to tissues where iron is utilized or stored.
Hemoglobin is an oxygen-binding protein in red blood cells. It is composed of four polypeptide subunits - two alpha chains and two beta chains - as well as a heme group containing iron. The heme group gives hemoglobin its red color and allows it to carry oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs. Mutations in hemoglobin genes can lead to hemoglobinopathies like thalassemias, sickle cell anemia, and hemoglobin M disease. These disorders disrupt hemoglobin's ability to carry oxygen and can cause anemia.
1) Porphyrins are biomarkers that can identify toxicity to the heme biosynthesis pathway. Disturbances can cause accumulations of porphyrin intermediates in urine.
2) Testing porphyrin levels can identify biochemical damage from toxic exposures like mercury and monitor chelation therapy. Abnormal levels also correlate with conditions like chemical sensitivities and neurological disorders.
3) Case studies show porphyrin testing identified arsenic exposure from an elevated ratio and confirmed mercury toxicity in an autistic child with challenges excreting heavy metals.
Hemoglobin is a protein in red blood cells that transports oxygen throughout the body. It is composed of four polypeptide subunits, each containing an iron-containing heme group that reversibly binds oxygen. The subunits are made of two alpha and two beta chains. Hemoglobin transports oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs for exhalation. Erythropoietin is a hormone that regulates red blood cell production and hemoglobin synthesis, and its release is stimulated by low oxygen levels in order to increase oxygen delivery capacity to tissues.
1) Bioenergetics examines the energy flow in living organisms using concepts like entropy, enthalpy, and free energy.
2) ATP acts as the energy currency of cells, being produced through exergonic reactions and consumed to power endergonic reactions.
3) Standard free energy changes can be added for coupled reactions and actual free energy depends on reactant and product concentrations, driving reactions towards or away from equilibrium.
Heme Structure. synthesis and porphyrias Ravi Kiran
This document discusses the structure of hemoglobin. It begins by stating that hemoglobin is a globular protein in red blood cells with a normal level of 14-16 g/dL in males and 13-15 g/dL in females. Hemoglobin is made up of four subunits, with each subunit containing one heme group and one globin polypeptide chain. The four subunits can either be two alpha and two beta chains (HbA), two alpha and two gamma chains (HbF), or two alpha and two delta chains (HbA2). The document then describes the structure of heme and how it attaches to the globin chain in each subunit to form hemoglobin.
The document discusses the structure of proteins at various levels of organization:
- Proteins are composed of amino acids linked together by peptide bonds to form polypeptide chains. The sequence and interactions of these chains determine the protein's structure.
- There are four levels of protein structure - primary, secondary, tertiary, and quaternary. Secondary structure includes alpha helices and beta sheets formed by hydrogen bonding between amino acids in the chain. Tertiary structure describes the overall 3D shape formed by interactions between amino acid side chains. Quaternary structure involves the interaction of multiple polypeptide chains.
- Protein structure enables proteins to perform their diverse functions through processes like enzyme catalysis, oxygen transport, and providing structure
the ionophores are the a part of membrane transport system. these slides include general concept of ionophores. useful for the paramedical, medical students.
ATP is the most important form of chemical energy in cells. It is a nucleoside triphosphate containing adenine, ribose, and three phosphate groups. ATP is considered the universal energy currency of cells because it can easily donate a single phosphate, two phosphates, or its entire adenosine group to drive various energy-requiring cellular reactions and processes. ATP is regenerated through substrate-level phosphorylation during glycolysis and the citric acid cycle, as well as oxidative phosphorylation in the mitochondria. When ATP is hydrolyzed, energy is released to power cellular work.
This document summarizes the four levels of protein structure: primary, secondary, tertiary, and quaternary. It provides details on each level: primary structure refers to the linear sequence of amino acids in the polypeptide chain. Secondary structure involves hydrogen bonding between amino acids to form regular structures like alpha helices and beta pleated sheets. Tertiary structure describes the overall 3D shape of the protein arising from secondary structures. Quaternary structure involves interactions between two or more polypeptide chains, as seen in hemoglobin which is made of four polypeptide subunits.
Haemoglobin is a protein in red blood cells that transports oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs. It is composed of haem and globin subunits. Globin is produced in polyribosomes while haem is produced in mitochondria and the two subunits combine to form functional haemoglobin. Abnormalities in haemoglobin structure or levels can impair oxygen delivery and cause anemia.
Protein ligand interaction by KK Sahu sirKAUSHAL SAHU
The document discusses protein-ligand interactions, providing examples of hemoglobin and antibodies. It explains that proteins interact specifically with ligands through binding sites, and this interaction is important for functions like oxygen transport and immune response. Hemoglobin transports oxygen through a cooperative binding process where the binding of oxygen to one subunit affects the affinity of nearby subunits. Antibodies also bind specifically to antigens through complementary interaction, which is vital for the immune system. The reversible and specific nature of protein-ligand binding allows for important biological processes and applications.
This document provides an overview of globular proteins, with a focus on hemoglobin and myoglobin. It discusses the following key points:
- Globular proteins have hydrophilic amino acids on the outside and hydrophobic amino acids on the inside, allowing them to be soluble in water. Hemoglobin and myoglobin are important globular proteins.
- Hemoglobin transports oxygen in red blood cells, while myoglobin stores and transports oxygen in muscle cells. Both contain a heme group that reversibly binds oxygen.
- The structures of myoglobin and each subunit of hemoglobin involve alpha helices that form a pocket holding the heme group. Histidine residues help bind the heme iron and oxygen.
- Hemoglobin
Hemoglobin is an iron-containing protein in red blood cells that transports oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs. It is a globular tetrameric protein composed of two alpha and two beta chains, with each chain containing a heme group that binds to oxygen. Hemoglobin undergoes a conformational change upon oxygen binding that makes the remaining binding sites have a higher affinity for oxygen in a cooperative binding process essential for oxygen transport.
- Hemoglobin (Hb) is an oxygen-transport protein found in red blood cells. It has a tetrameric structure composed of two alpha and two beta subunits, each containing an iron-containing heme group that reversibly binds oxygen.
- Hb binds oxygen cooperatively, meaning that the binding of oxygen to one subunit increases the affinity of the other subunits for oxygen. This allows for efficient oxygen uptake in the lungs and release in tissues.
- Factors like pH, carbon dioxide levels, and 2,3-bisphosphoglycerate regulate Hb's affinity for oxygen and allow for oxygen delivery to tissues where it is needed. Sickle cell anemia results from a mutation that causes Hb to polymer
Hemoglobin is a conjugated protein found in red blood cells that carries oxygen from the lungs to tissues and carbon dioxide from tissues to the lungs. It is composed of globin and heme. Globin contains four polypeptide chains (two alpha and two beta or gamma or delta chains) and four heme groups. Heme contains iron that reversibly binds oxygen. Hemoglobin binding of oxygen is cooperative, allowing for efficient oxygen delivery to tissues. Its affinity for oxygen decreases in tissues due to Bohr and BPG effects, promoting oxygen release to tissues.
Metalloporphyrins with special reference to Iron porphyrins ( Haemoglobin and...ADITYA ARYA
Metalloporphyrins with special reference to Iron
porphyrins ( Haemoglobin and Myoglobin )
Porphyrins are one of the most important groups of
bioinorganic compounds in which a metal ion is
surrounded by the four nitrogens of porphin ring.
❑ Porphines are made of four pyrrole rings linked
together through methene bridges.
❑ Therefore, porphines have macrocylic pyrrole system
with conjugated double bonds as shown here:
❑ These porphines act as tetradentate ligands with four
nitrogen donor sites.
Two of these are tertiary nitrogen donor positions which can form
coordinate bonds by donating a pair of electrons each to the metal
ion.
❑ The other two are secondary nitrogen donor positions. each of
which lose a proton in forming a coordinate bond with a metal
ion.
❑ Thus, a porphin ring acts as a tetradentate dinegative ligand (or
dianion).
❑ Dipositive cations such as Mg2+ Fe2+ or Ni2+ are capable of
forming neutral complexes with porphine as shown here:
❑ Four pyrrole rings of porphin carrying substituents other than hydrogen
are called porphyrins. The complexes in which a metal ion is held in
the porphyrin ring system are called metalloporphyrins.
❑ Such complexes play a vital role in biological systems.
The document discusses the molecular basis of hemoglobin and hemoglobinopathies. It describes the structures and functions of myoglobin and hemoglobin, comparing their oxygen binding properties. Hemoglobin has a sigmoidal oxygen binding curve due to its allosteric properties arising from quaternary structure. Effectors like CO2, H+, chloride ions, and 2,3-BPG regulate hemoglobin's affinity for oxygen. The molecular basis of sickle cell anemia is explained, with the point mutation causing hemoglobin tetramers to aggregate and deform red blood cells, clogging capillaries. ELISA principles and importance for serodiagnosis of infectious diseases is briefly outlined.
Hemoglobin and myoglobin are metalloproteins that carry oxygen in organisms. Hemoglobin transports oxygen from the lungs to tissues via the bloodstream. It contains four subunits, each with an iron-containing heme group that reversibly binds oxygen. Myoglobin stores oxygen in muscle tissues. It contains a single polypeptide chain with a heme group. Both proteins release oxygen in tissues through cooperativity and the Bohr effect, which decreases their oxygen affinity under acidic conditions produced by cellular respiration. Diseases like sickle cell anemia arise from mutations altering hemoglobin structure and function.
This is based on protein-ligand interaction physical method, which gives us knowledge about how our body protein interacts with other molecule and protein function.
This document discusses the structure and function of haemoglobin and the transport of gases in the blood. It provides a history of discoveries about haemoglobin dating back to the 17th century. Key points covered include the tetrameric structure of haemoglobin, with each subunit binding one heme group and iron atom. Haemoglobin is able to efficiently transport oxygen and carbon dioxide via changes in its quaternary structure and binding of effectors like hydrogen ions, carbon dioxide and 2,3-BPG. The sigmoidal oxygen dissociation curve illustrates haemoglobin's ability to load and unload oxygen in the lungs and tissues respectively. Factors like pH, temperature and organic phosphates influence the curve.
The structure of a protein determines its function. For enzymes, the binding site or active site allows substrates to bind via lock-and-key or induced fit mechanisms. Myoglobin and hemoglobin both contain heme groups to bind oxygen, but differ in structure - myoglobin is spherical while hemoglobin is a tetramer. This allows hemoglobin to exhibit cooperative binding and transport oxygen more efficiently than myoglobin via conformational changes.
The structure of a protein determines its function. For enzymes, the binding site or active site allows substrates to bind via lock-and-key or induced fit mechanisms. Myoglobin and hemoglobin both contain heme groups to bind oxygen, but differ in structure - myoglobin is spherical while hemoglobin is a tetramer. This allows hemoglobin to exhibit cooperative binding and transport oxygen more efficiently than myoglobin via conformational changes.
Gas exchange occurs in the alveoli of the lungs where oxygen diffuses from the inhaled air into the blood and carbon dioxide diffuses out of the blood and into the exhaled air. Hemoglobin is responsible for carrying oxygen in the blood from the lungs to tissues and carrying carbon dioxide back to the lungs from tissues. Hemoglobin has a higher affinity for oxygen when oxygen levels are high, like in the lungs, and a lower affinity when oxygen levels are low, like in tissues, through a cooperative binding mechanism that allows for efficient oxygen delivery throughout the body. Myoglobin stores and facilitates oxygen transport within muscle cells.
Hemoglobin and myoglobin are hemeproteins that transport oxygen in the body.
Myoglobin stores and transports oxygen in muscle cells. It has a higher affinity for oxygen than hemoglobin and binds one oxygen molecule. Hemoglobin transports oxygen from the lungs to tissues. It has four subunits that cooperatively bind four oxygen molecules in a sigmoidal binding curve. This allows hemoglobin to efficiently deliver oxygen to tissues in response to changes in oxygen levels. Key differences between the two proteins relate to their quaternary structure, cooperative binding, and oxygen dissociation curves.
HEMOGLOBIN - STRUCTURE IN RELATION TO FUNCTIONMuunda Mudenda
Hemoglobin is a protein in red blood cells that transports oxygen and carbon dioxide throughout the body. There are three main types of hemoglobin in humans: hemoglobin A, hemoglobin F, and hemoglobin A2. Hemoglobin has a structure of four subunits, each containing a globular protein chain and a heme group with iron. The structure allows hemoglobin to reversibly bind oxygen in the lungs and release it in tissues through a conformational change between tense and relaxed states. Diseases can arise from structural variants that decrease stability or from disorders in globin chain synthesis.
Role of co-ordination chemistry in myoglobin chemistry MyoglobinMaryumAkhter
in this presentation, one can see the structure, properties, function, binding capacity with Carbon dioxide and oxygen, co-ordination chemistry in myoglobin, difference and similarities with haemoglobin.
Haemoglobin is the protein in red blood cells that transports oxygen and carbon dioxide throughout the body. It is composed of four globin protein subunits, each containing an iron-containing heme group. Haemoglobin's ability to bind and release oxygen and carbon dioxide allows it to deliver oxygen from the lungs to tissues and remove carbon dioxide from tissues back to the lungs. Several factors regulate haemoglobin's affinity for oxygen, including partial pressures of oxygen and carbon dioxide, pH, and levels of 2,3-bisphosphoglycerate in the blood. This complex regulation allows haemoglobin to efficiently load and unload gases where they are needed.
This document summarizes key information about hemoglobin, including its structural features, cooperative effect, Bohr effect, oxygen dissociation curve, functions, and some disorders. Hemoglobin is an iron-containing protein in red blood cells that transports oxygen throughout the body. It consists of four globin protein subunits and four heme groups, each containing an iron ion that can bind to one oxygen molecule. The binding of oxygen to one subunit causes a conformational change that makes the other subunits more likely to bind oxygen as well, in a cooperative effect. The Bohr effect describes how increased carbon dioxide levels enhance the release of oxygen from hemoglobin in tissues. The oxygen dissociation curve illustrates hemoglobin's sigmoidal binding of oxygen across
Hemoglobin and myoglobin are two important proteins involved in the transport...tekalignpawulose09
1. Hemoglobin:
• Hemoglobin is found in red blood cells and is responsible for carrying oxygen from the lungs to the tissues and organs of the body.
• It consists of four protein subunits, each containing a heme group with an iron atom that binds to oxygen.
• Hemoglobin also helps in the transport of carbon dioxide from tissues back to the lungs for exhalation.
• The function of hemoglobin is vital for the body's oxygen transport system and overall metabolism.
2. Myoglobin:
• Myoglobin is a protein found in muscle tissues and serves as an oxygen reservoir for muscle cells.
• It contains a single heme group that binds to oxygen, similar to hemoglobin.
• Myoglobin stores oxygen in muscle cells and releases it when needed, helping in the supply of oxygen during muscle activity.
• This protein helps muscles sustain aerobic metabolism and endurance during physical activities.
Similar to [Brief]Structure and functions of hemoglobin and myglobin (Bio-Inorganic chemistry) (20)
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2. Contents:
1. Brief Introduction
2. Myoglobin and Hemoglobin Basics
3. Structure of Heme prosthetic group and oxygen
binding
4. Graphs related to Hemoglobin and Myoglobin
5. Explanation of Graphs
6. Structure of Hemoglobin and Myoglobin Active
sites
7. Selective Binding of Dioxygen with Hemoglobin
and Myoglobin
8. Functions of Hemoglobin and Myoglobin
9. Comparison between hemoglobin and myglobin
3
5
7
9
10
11
13
14
15
Page
No.
3. Brief Introduction
• Iron is the most abundant transition metal found in biological system with a percentage of weight
in human body approximately 5 x 10-3% Hence, this is no surprising fact that there is a myriad of
Iron-containing proteins and enzyme in biological systems
Iron Containing species can be
categorized in two categories
Non Porphyrin Ligand System
Non-Heme, Iron containing Proteins
Porphyrin ligand system--- An Iron
bearing Heme moiety.
**Hemoglobin and
Myoglobin Falls
under this Category
4. • Myoglobin(Mb) and Hemoglobin(Hb) is an essential part in maintaining the biological functions.
Dioxygen(O2) solubility in water is as low as 6.6cm3/Liter or 3 x 10-4M but myoglobin and
hemoglobin increases the solubility of dioxygen by 30 folds making it 200 c.m3/Liter.
• The Myoglobin and Hemoglobin forms complex with Iron through prosthetic heme group, a planar
Four-coordinated porphyrin ligand. The protein side chain, ε-nitrogen(Imidazole Nitrogen) atoms of
histidine completes iron’s ligand coordination sphere in Mb and Hb.
The Heme Group found in Hemoglobin and
Myoglobin
5. Myoglobin and Hemoglobin Basics
• Myoglobin(Mb) is globular monomeric, protein containing a single polypeptide chain of 160 Amino
acid residues made of six α-Helical segments and six nonhelical segments
• Myoglobin heme prosthetic group center contains an iron ion complexed by a porphyrin called
protoporphyrin IX.
• The Iron [Fe(II)] protoporphyrin cofactor is held in place in the protein by noncovalent hydrophobic
interactions of about 80 residues generally Leucine, Isoleucine, Valine and phenylalanine and one
covalent linkage at the proximal Histidine residue (Also known as his93).
• Myoglobin stores Oxygen in muscles and other cellular tissue binding one oxygen atom per protein
subunit.
• Hemoglobin a tetramer of four globular protein subunits, transports oxygen through the blood
plasma. Hemoglobin’s Four subunits comprises two α-Chains of 141 residues and two β-Chains of 146
residues making up a total molecular weight of 64.5KDa.
• Hemoglobin Binds to O2 in a Cooperative Manner- That is, Once a O2 molecule attaches to the
enzyme then the 2nd, 3rd, 4th O2 attaches themselves more readily. For attachment of O2 in both the
Hemoglobin and Myoglobin it is prerequisite that the Iron should be present in it’s reduced state i.e.
Fe(II) state. The terms oxy- and deoxy- in hemoglobin and myoglobin is used to show oxygenated and
deoxygenated Hemoglobin or Myoglobin with Fe(II) in both. While the Met- refers to oxygenated
heme proteins having Fe(III) centers.
6. O2 + 4H + 4e- 2H2O E0= +0.82V
Hb(Fe3+) + e- Hb(Fe2+) E0= +0.17V
*The comparison of reduction potential in above reaction shows that dioxygen should oxidize Fe(II)
Circumstances favoring heme-O2 Stability:-
1. Placement of heme in hydrophobic pocket with enzymes that is inaccessible to water
molecules and protons
2. A bent binding mode for O2 favoured by the prosthetic group’s pocket shape that prevent
μ-oxo dimerization.
3. σ-Bonding donation from an sp2-hybridized superoxide ion to empty d2
z Fe(II) orbital
facilitated by bent orientation of bound O2 and formation of π-back bonds through
interaction of a half filled dxz orbital of Fe(II) with a half filled π* orbital of superoxide ion.
7. Structure of Heme Prosthetic Group and
Oxygen Binding
• Deoxymyoglobin and deoxyhemoglobin contain pentacoordinate Fe(II) center in which the
metal ion lies out of plane of porphyrin’s four pyrrole-nitrogen donor ligands.
Perutz has called this state as the T or Tense state, The T state is a term which describes the
quaternary structure of Hb teramer which is one of low oxygen affinity in which protein is
restrained by binding of Proximal Histidine. In the T state the Fe(II) center is held at
approximately 0.55A (Angstrom) outside of the porphyrin plane and no Hb subunit out of four
posses dioxygen ligand atom.
• The porphyrin ring is also anchored at the active site by iron’s coordination to proximal
histidine’s Imidazole Nitrogen.
T-State
R-State
• In R-State or relaxed quaternary state dioxygen is bound to iron on the so called distal side of the
porphyrin ring.
• Switching from T-State to R-State in Hb tetramer takes place during or after binding of approx. two
dioxygen molecules, this binding of dioxygen relieves the constrains within the surrounding protein
matrix allowing the Iron atom to move back into the porphyrin plane.
8. • Binding of sixth ligand dioxygen and consequent movement of the Fe atom back into the plane of
porphyrin includes a tertiary structural change as the proximal Histidine changes its bond angle with iron
atom. The F-Helix which contains the proximal histidine also changes position
• In hemoglobin these factors in turn change he quaternary structure of Hb tetramer and influence the
affinity of the hemes for dioxygen.
• The metal ion movement into the porphyrin plane is accompanied by a spin change of high (S=2) to low
spin (S=1/2) and Fe(II) to Fe(III), Fe ion become smaller hence better fits into the cavity. The Dioxygen
molecule is guided by the protein pocket surrounding it to attach in a bent structure with an Fe-O-O bond
angle of 115o.In oxidation of Fe(II) to Fe(III) the dioxygen becomes superoxide.
Pictures showing transition from T-State to R-State
10. (a) A curve describing the binding of oxygen to myoglobin. The partial pressure of O2 in the air above the solution is
expressed in kilopascals (kPa). Oxygen binds tightly to myoglobin, with a P50 of only 0.26 kPa. The equation which
describes the curve is:-
(b) A sigmoid (cooperative) binding curve. A sigmoid binding curve can be viewed as a hybrid curve reflecting a
transition from a low-affinity to a high-affinity state. Cooperative binding, as manifested by a sigmoid binding curve,
renders hemoglobin more sensitive to the small differences in O2 concentration between the tissues and the lungs,
allowing hemoglobin to bind oxygen in the lungs (where pO2 is high) and release it in the tissues (where pO2 is low).
(c) Effect of pH on the binding of oxygen to hemoglobin. The pH of blood is 7.6 in the lungs and 7.2 in the tissues.
Experimental measurements on hemoglobin binding are often performed at pH 7.4
(d) Effect of BPG on the binding of oxygen to hemoglobin. The BPG concentration in normal human blood is about
5 mM at sea level and about 8 mM at high altitudes. Note that haemoglobin binds to oxygen quite tightly when BPG
is entirely absent, and the binding curve appears to be hyperbolic. In reality, the measured Hill coefficient for O2-
binding cooperativity decreases only slightly (from 3 to about 2.5) when BPG is removed from hemoglobin, but the
rising part of the sigmoid curve is confined to a very small region close to the origin. At sea level, hemoglobin is
nearly saturated with O2 in the lungs, but only 60% saturated in the tissues, so the amount of oxygen released in
the tissues is close to 40% of the maximum that can be carried in the blood. At high altitudes, O2 delivery declines
by about one-fourth, to 30% of maximum. An increase in BPG concentration, however, decreases the affinity of
hemoglobin for O2, so nearly 40% of what can be carried is again delivered to the tissues.
Explanation of Graphs
11. Structure of Hemoglobin and Myoglobin Active
Site
• First X-Ray crystallographic studies regarding eluciding structure of Mb and Hb was done in 1966 and
1975 respectively. The scientists have also studued the carbon monoxide bound moieties of MbCO and
HbCO as well as MbNO.
• Site directed mutagenesis of residues near the active site of Hb and Mb have yielded info on the exact
nature of the O2, CO, NO binding and the small molecule’s orientation at heme site.
• These studies were confirmed by many other analytical techniques and a clear picture of
metalloprotein’s active site emerged out.
• The active site of Hb/Mb contains an Fe(II) proporphyrin IX encapsulated in a water resistant pocket
and bound to protein through single coordination bond between Imidazole Nitrogen of proximal
Histidine(his93, F8 for Mb) and Fe(II). Additionally, Leucine, Isoleucine, Valine, Phenylalanine interact
with heme, holding it in place through hydrophobic interactions.
• The five coordinate Fe(II) can add O2 in its sixth vacant coordination site, and also a variety of other
small ligands (CO,NO,RCN). When O2 is bound, it is stabilized by hydrogen bond interactions through
the distal Histidine (his64, E7). The hydrogen bond interaction may affect O2 affinity and inhibit
pathways leading to further oxidation and μ-oxo dimerization.
12. • Despite the many model compounds that have been prepared, picket fence porphyrin, fist reported by
Collman research group in 1974, remains the only porphyrin type ligand system yielding crystallographic data
comparable to Mb oxyheme stereochemistry.
Distal histidine hydrogen bonding structure for hemoglobin (left) and a heme model
(right)
13. Selective Binding of O2 over CO in Hemoglobin
and Myoglobin
The Selective binding of O2 rather CO in wild type biological systems is complicated by the fact that
naturally occurring metalloprotein include Hemoglobin and Myoglobin produce CO during degradation
process. Therefore, hemes must be able to carry out their oxygen transport and storage functions in
presence of significant concentration of CO. In addition, CO binds to Mb and HB with affinity of respectively
25 and 200 times those of O2. The discrimination (As suggested by Collmen) is based on steric hindrance
constrains imposed by amino acids residues on distal side of porphyrin and by selective Hydrogen bond
favoring O2 over CO. O2 is capable of bent geometry when bound to heme facilitating the Hydrogen bond
to distal histidine, whereas CO preferred linear binding mode not only prevents hydrogen bond formation
but also results in steric clashes with neighbouring amino acids. For synthetic system of picket-fence,
Pocket, capped porphyrin, CO affinity exceeds that for O2 sometimes by many orders of magnitude.
Also for small-molecules, metal-carbon monoxide complexes, the carbon monoxide ligand is almost always
in a linear conformation and perpendicular to metal. If one assumed bonding of CO to Hb or Mb in its
normal linear perpendicular mode then steric conflicts would occur and hence CO binding would be less
favoured.
14. Functions of Myoglobin and Hemoglobin
• Hemoglobin transports oxygen from lungs to tissues, lungs are the loading point of oxygen in hemoglobin
because partial pressure of dioxygen here is more and unloading point is tissue because dioxygen partial
pressure is less here. Also, it has a essential role as carrier because the solubility product of dioxyegn is
quite low in water based plasma and hemoglobin makes increases the solublity my many folds, therefore
acting as a efficient carrier
• Hemoglobin also transports Carbon Dioxide back to lungs and also maintains acid base balance in blood (As
a buffer).
• The hemoglobin gives the blood its characteristic Red colouration. The hemoglobin acts as a physiologically
active catabolite, It plays a crucial role in erythrocyte metabolism
• Myoglobin has a strong affinity for binding for oxygen, which makes it able to store it effectively in muscles.
• Myoglobin helps body at the starving situation of oxygen, especially in the anaerobic situation.
• Myoglobin helps in regulating body temperature.
16. References:-
1. Lippard, Principles of Bioinorganic Chemsitry, 1st Edition
2. Leninger, Principles of Biochemistry, 3rd Edition
3. Rossette, Bioinorganic Chemistry-A short course, Wiley, 2nd Edition
4. Britannica.com, Hemoglobin and Myoglobin
5. Wiley Online Library, Foundation course in Biochemistry
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