Proteins are the working molecules of cells that carry out functions encoded by genes. They include structural proteins, transport proteins, regulatory proteins, and signaling proteins. There are four levels of protein structure: primary, secondary, tertiary, and quaternary. Protein function derives from its three-dimensional structure, which is specified by the amino acid sequence. Chaperone proteins assist in protein folding to ensure proteins reach their correct native conformation. Post-translational modifications and interactions with ligands allow regulation of protein activity, while misfolded proteins are degraded through ubiquitination or lysosomal pathways.
Protein Structure, Post Translational Modifications and Protein FoldingSuresh Antre
Post-translational modifications (PTMs) are covalent processing events that change the properties of a protein by proteolytic cleavage or by addition of a modifying group to one or more amino acids.
Protein post-translational modification (PTM) plays an essential role in various cellular processes that modulates the physical and chemical properties, folding, conformation, stability and activity of proteins, thereby modifying the functions of proteins
Post translation modifications(molecular biology)IndrajaDoradla
description of post translation modifications which include folding,proteolytic clevage and chemical modification and protein splicing and protein degradation
Chaperones are a functionally related group of proteins that assist the covalent folding or unfolding and the assembly or disassembly of other macromolecular structures.
Introduction
Protein modifications
Folding
Chaperon mediated
Enzymatic
Cleavage
Addition of functional groups
Chemical groups
Hydrophobic groups
Proteolysis
Conclusion
Reference
Protein Structure, Post Translational Modifications and Protein FoldingSuresh Antre
Post-translational modifications (PTMs) are covalent processing events that change the properties of a protein by proteolytic cleavage or by addition of a modifying group to one or more amino acids.
Protein post-translational modification (PTM) plays an essential role in various cellular processes that modulates the physical and chemical properties, folding, conformation, stability and activity of proteins, thereby modifying the functions of proteins
Post translation modifications(molecular biology)IndrajaDoradla
description of post translation modifications which include folding,proteolytic clevage and chemical modification and protein splicing and protein degradation
Chaperones are a functionally related group of proteins that assist the covalent folding or unfolding and the assembly or disassembly of other macromolecular structures.
Introduction
Protein modifications
Folding
Chaperon mediated
Enzymatic
Cleavage
Addition of functional groups
Chemical groups
Hydrophobic groups
Proteolysis
Conclusion
Reference
This Presentation Deals With The Proteins And Their Different Structures. In This Presentation, You Will Learn About What Are Proteins, Importance Of Proteins, Structures Of Proteins, Primary Structure, Secondary Structure, Tertiery Structure, Quaternery Structure, Biological Examples With References For Further Studies.
Assembly of Macromolecular Complexes
Carbohydrate
Proteins
Nucleic acid
*Presented By:
Abubakar Mustapha
Pharm. D Third Year, Integral University Lucknow, UP, India
Folding depends upon sequence of Amino Acids not the Composition. Folding starts with the secondary structure and ends at quaternary structure.
Denaturation occur at secondary, tertiary & quaternary level but not at primary level.
This Presentation Deals With The Proteins And Their Different Structures. In This Presentation, You Will Learn About What Are Proteins, Importance Of Proteins, Structures Of Proteins, Primary Structure, Secondary Structure, Tertiery Structure, Quaternery Structure, Biological Examples With References For Further Studies.
Assembly of Macromolecular Complexes
Carbohydrate
Proteins
Nucleic acid
*Presented By:
Abubakar Mustapha
Pharm. D Third Year, Integral University Lucknow, UP, India
Folding depends upon sequence of Amino Acids not the Composition. Folding starts with the secondary structure and ends at quaternary structure.
Denaturation occur at secondary, tertiary & quaternary level but not at primary level.
Introduction-
Levinthal paradox
Biophysical aspects of protein folding
Hierarchy in protein structure
Thermodynamic stability
Cellular aspects of protein folding
Self assembly (folding) of protein
Molecular assistance – Chaperons
Enzymes involved in protein folding
Conclusions
References
regeneration
Proliferative Capacities of Tissues
Stem Cells
REPAIR BY CONNECTIVE TISSUE
Angiogenesis
Migration of Fibroblasts and ECM Deposition (Scar Formation)
PATHOLOGIC ASPECTS OF REPAIR
What is wound healing?
Classification of Wounds
Classification of Wounds Closure
Risk Factors for Surgical Wound Infections
Antibiotic Use
Hypertrophic Scars and Keloids
25.1Digestion and Absorption of Lipids
25.2Triacylglycerol Storage and Mobilization
25.3 Glycerol Metabolism
25.4 Oxidation of Fatty Acids
25.5 ATP Production from Fatty Acid Oxidation
25.6 Ketone Bodies
25.7 Biosynthesis of Fatty Acids: Lipogenesis
25.8 Relationship Between Lipogenesis and Citric Acid Cycle Intermediates
25.9 Fate of Fatty-Acid Generated Acetyl CoA
25.10 Relationships Between Lipid and Carbohydrate Metabolism
25.11B Vitamins and Lipid Metabolism
24.1 Digestion and Absorption of Carbohydrates
24.2 Hormonal Control of Carbohydrate Metabolism
24.3 Glycogen Synthesis and Degradation
24.4 Gluconeogenesis
24.5 The Pentose Phosphate Pathway
24.6 Glycolysis
24.7 Terminology for Glucose Metabolic Pathways
24.8 The Citric Acid Cycle
24.9 The Electron Transport Chain
24.10 Oxidative Phosphorylation
24.11 ATP Production for the Complete Oxidation of Glucose
24.12 Importance of ATP
24.13 Non-ETC Oxygen-Consuming Reactions
24.14 B-Vitamins and Carbohydrate Metabolism
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
Overview on Edible Vaccine: Pros & Cons with Mechanism
Bio108 Cell Biology lec7b PROTEIN STRUCTUREAND FUNCTION
1.
2. Proteins - are the working molecules of a cell which carry out the
program of activities encoded by genes
Enzymes- substances capable of catalyzing an incredible range of
intracellular and extracellular chemical reactions with speed
and specificity
Proteome- refers to the entire protein complement of an organism
TERMINOLOGY
3. Structural Proteins - provide structural rigidity to the cell
Transport Proteins - control the flow of materials across
cellular membranes
Regulatory Proteins - act as sensors and switches to
control protein activity and gene function
Signaling Proteins - transmit external signals to the cell
interior (includes cell surface
receptors)
Motor Proteins - cause motion
4.
5. Key Concepts:
Only when a protein is in its correct three-dimensional structure, or conformation, is it
able to function efficiently.
Function is derived from three-dimensional structure, and three-dimensional structure is
specified by amino acid sequence.
Primary Structure of Proteins (Linear)
Structure of a Tripeptide
6. Primary structure of a protein is simply the linear arrangement, or sequence, of
the amino acid residues that compose it.
Peptide- a short chain of amino acids linked by peptide bonds and having a
defined sequence.
Polypeptide- longer chains of amino acids
Secondary Structure of Proteins
α- Helix
α
7. In the absence of stabilizing noncovalent interactions, a
polypeptide assumes a random-coil structure.
When stabilizing hydrogen bonds form between certain
residues, parts of the backbone fold into one or more well-
defined periodic structures:
alpha (α) helix
beta (β) sheet
short U-shaped turn
In an average protein, 60 percent of the polypeptide chain
exist as -helicesα and -sheetsβ ; the remainder of the
molecule is in random coils and turns.
8. Tertiary Structure of Proteins
Various Graphic Representations of A Tertiary Structure
9. (a) Two helices connected by a short loop in a
specific conformation constitute a helix-
loop-helix motif. This motif exists in many
calcium-binding and DNA-binding
regulatory proteins.
(b) The zinc-finger motif is present in many
DNA-binding proteins that help regulate
transcription.
10. o The simplest way to represent three-dimensional structure is to trace the course of the
backbone atoms with a solid line (fig. A) while the most complex model shows every
atom(fig. B).
o The solvent-accessible surface model (fig. D) conveys information about the protein
surface where other molecules bind. On this water-accessible surface, regions having a
common chemical character (hydrophobicity or hydrophilicity) and electrical character
(basic or acidic) can be mapped.
Quaternary Structure of Proteins
(Multimeric)
- consist of three or more polypeptides or subunits
- describes the number (stoichiometry) and relative
positions of the subunits in multimeric proteins
- (at the right) Hemagglutinin, a quaternary structure
11. Macromolecular Assemblies
o an example is the capsid that encases the viral genome and bundles of cytoskeletal
filaments that support and give shape to the plasma membrane
o other macromolecular assemblies act as molecular machines, carrying out the most
complex cellular processes by integrating individual functions into one coordinated process
mRNA Transcription Machineries
12. Protein folding is needed to generate the structure of the final protein.
Incorrectly folded proteins usually lack biological activity and, in some cases, may
actually be associated with disease.
To correct misfoldings, the cell has error-checking processes that eliminate
incorrectly synthesized or folded proteins.
Any polypeptide chain containing n residues could fold into 8n
conformations.
native state- the most stably folded form of the molecule
What guides proteins to their native folded state?
protein folding is a self-directed process
sufficient information must be contained in the protein’s primary sequence to direct correct
folding
In vitro studies showed that:
Thermal energy from heat
extremes of pH
Chemicals
These factors disrupt the weak noncovalent interactions that stabilize the native
conformation of a protein.
13. Although protein folding occurs in vitro, only a minority of unfolded molecules undergo
complete folding into the native conformation within a few minutes.
Chaperones- a class of proteins found in all organisms from bacteria to humans
- are located in every cellular compartment
- function in the general protein-folding mechanism of cells
Two general families of chaperones are recognized:
■ Molecular chaperones - bind and stabilize unfolded or partly folded proteins
■ Chaperonins- directly facilitate the folding of proteins
Chaperone- mediated Protein Folding
14.
15. Chaperones function is to assist the assembly process,
they do not convey additional information necessary for folding into
the correct conformation.
The folded conformation is determined by the amino acid sequence.
- function by stabilizing unfolded or partially folded
polypeptides that are intermediates along the pathway leading to
the final correctly folded state.
16. Chaperones stabilize unfolded proteins which prevents the
accumulation of incorrectly folded proteins. As you know protein misfolding
could have very bad consequences.
For example, misfolded proteins can aggregate to form insoluble
fibers called amyloid fibers. These fibers accumulate in the extracellular
spaces and within cells and are characteristic of several
neurodegenerative disease such as Parkinson’s and Alzheimer’s disease.
Two types of chaperone proteins:
1) heat shock proteins and
2) chaperonins Found in the cytosol and sub
cellular organelles of eukaryotic
cells
* HSP (heat shock protein) - stabilize and facilitate the refolding of
proteins that have been partially denatured as a result of exposure to
elevated temperatures.
17. They bind short hydrophobic regions of unfolded polypeptides. This maintains the
polypeptide chain in an unfolded conformation and prevents aggregation.
The E.coli Hsp70 which include proteins called Hsp70coded by dnaK gene, and
Hsp40 coded by dnaJ gene and the GrpE.
The chaperons bind to hydrophobic regions of the proteins, including proteins
that still are being translated. They prevent aggregation by holding the protein in an
open confirmation until it is completely synthesized and ready to fold.
They also are involved in other processes that require shielding of hydrophobic
regions.
18. *Chaperonins function to protect unfolded polypeptides
from proteolysis in the cytoplasm.
Chaperonins consist of multiple protein subunits
arranged in two stacked rings to form a double chambered
structure. This allows protein folding to occur without
aggregation of unfolded segments.
The main version of which is E. coli is GroEL/GroEs
complex. The complex is a multisubunit structure that looks
like a hollowed-out bullet. Protein enters unfolded and
exists folded.
19. Chaperonin-Mediated Protein Folding
Mechanisms:
1. Partly folded or misfolded polypeptide is inserted into the cavity of GroEL.
2. The protein then binds to the inner wall and folds into its native
conformation.
3. In an ATP-dependent step, GroEL undergoes a conformational change and
releases the folded protein, a process assisted by GroES.
20. Acetylation - the addition of an acetyl group (CH3CO) to the amino group of the N-terminal
residue
Phosphorylation - addition and removal of phosphate groups from serine, threonine, or tyrosine
residues
Glycosylation - the attachment of linear and branched carbohydrate chains
Hydroxylation -introduction of one or more hydroxyl groups (-OH) into a compound (or radical)
Methylation -the attachment or substitution of a methyl group on various substrates
Carboxylation -the addition of carbon dioxide or bicarbonate to form a carboxyl group
21. Protein Degradation
Ubiquitin-mediated
Proteolytic
Pathway
1. Enzyme 1 (E1) is activated by attachment of a
ubiquitin (Ub) molecule.
2. It then transfers this Ub molecule to E2.
3. Ubiquitin ligase (E3) transfers the bound Ub
molecule on E2 to the side-chain —NH2 of a
lysine residue in a target protein.
4. Additional Ub molecules are added to the target
protein by repeating steps, forming a
polyubiquitin chain that directs the tagged
protein to a proteasome.
5. Within this large complex, the protein is cleaved
into numerous small peptide fragments.
22. -In eukaryotic cells there are 2 major pathways that
mediate protein degradation:
1) ubiquitin-proteasome
2)lysosomal proteolysis pathway which
involves the uptake and digestion of proteins by the
lysosomes.
-Many rapidly degraded proteins function as regulatory
molecules such as transcription factors, particularly those
that are involved in mediating cell proliferation and cell
survival.
-This allows for their levels to change very
rapidly in response to external stimuli.
-Other proteins are rapidly degraded in response to
specific signals. Also, faulty or damaged proteins are
recognized and rapidly degraded within cells, thereby
eliminating the consequences of mistakes made during
protein synthesis.
23. Digestive Proteases
Endoproteases- attack selected peptide bonds within a polypeptide chain.
The principal endoproteases are pepsin, which
preferentially cleaves the backbone adjacent to
phenylalanine and leucine residues, and trypsin and
chymotrypsin, which cleave the backbone adjacent to
basic and aromatic residues.
Exopeptidases- sequentially remove residues from the N-terminus
(aminopeptidases) or C-terminus (carboxypeptidases) of
a protein.
Peptidases - split oligopeptides containing as many as about 20
amino acids into di- and tripeptides and individual amino
acids.
24. Mutation leads to Misfolding
Such misfolding then leads to loss of normal function and marks it for proteolytic
digestion.
Proteolytic fragments accumulate in various organs.
Some Neurodegenerative Diseases caused by accumulation
of plaques:
a) Alzheimer’s Disease
b) Parkinson’s Disease
c) Spongiform Encephalopathy in cows
25. Two Properties of Protein-Ligand Interaction:
1. Specificity - the ability of a protein to bind one molecule in preference to other
molecules
2. Affinity -the strength of binding
Both the specificity and the affinity of a protein for a ligand depend on the structure of the
ligand-binding site.
For high-affinity and highly specific interactions to take place, there must be molecular
complementarity.
An example is the antibody-antigen complex:
The hand-in-glove fit between an antibody and an
epitope on its antigen—in this case, chicken egg-
white lysozyme. Regions where the two molecules
make contact are shown as surfaces.
The antibody contacts the antigen with residues
from all its complementarity-determining regions
(CDRs).
In this view, the complementarity of the antigen
and antibody is especially apparent where
“fingers” extending from the antigen surface are
opposed to “clefts” in the antibody surface.
26. Enzymes
Catalysts of chemical reactions in cells.
Increase the reaction rates by lowering the activation energy of chemical reactions
Two Striking Properties of Enzymes:
Catalytic power- causes the rates of enzymatically catalyzed reactions to be 106
–1012
times that of
their corresponding uncatalyzed reactions under similar conditions.
Specificity - ability to act selectively on one substrate or a small number of chemically similar
substrates
Effect of a Catalyst on the Activation Energy of a Chemical Reaction
27. Enzymes have active sites where substrates could bind.
Two Regions of the Active site:
1. Binding Region
2. Catalytic Region
Protein kinase A and conformational change induced by substrate
binding
28. Enzymes in a Common Pathway Are
Often
Physically Associated with One
Another
Evolution of Multifunctional Enzyme
(a) When the enzymes are free in solution or even constrained within the same cellular compartment, the
intermediates in the reaction sequence must diffuse from one enzyme to the next, an inherently slow
process.
(b) Diffusion is greatly reduced or eliminated when the enzymes associate into multisubunit complexes.
(c) The closest integration of different catalytic activities occurs when the enzymes are fused at the genetic
level, becoming domains in a single protein.
29. Motor Proteins - specialized enzymes used by the cells to generate the forces
necessary for many cellular movements
- generate either linear or rotary motion
Three general properties of motor proteins:
1. The ability to transduce a source of energy, either ATP or an ion gradient, into linear or rotary
movement
2. The ability to bind and translocate along a cytoskeletal filament, nucleic acid strand, or protein
complex
3. Net movement in a given direction
Linear and Rotary Motor Proteins
30. Allostery- refers to any change in a protein’s tertiary or quaternary structure or both
induced by the binding of a ligand, which may be an activator, inhibitor,
substrate, or all three.
Ligand-induced Activation of Protein Kinase A (PKA) Switching Mediated by Ca2+/Calmodulin
31. Regulation of Protein Activity by Kinase/Phosphatase Switch
Phosphorylation- addition and removal of phosphate groups from serine, threonine,
or tyrosine residues
Protein kinases catalyze phosphorylation while phosphatases catalyze
dephosphorylation.
All classes of proteins—including structural proteins, enzymes, membrane channels, and
signaling molecules—are regulated by kinase/phosphatase switches.
32. Purifying Techniques
1. Centrifugation
Principle:
Two particles in suspension (cells, organelles, or molecules) with
different masses or densities will settle to the bottom of a tube at
different rates.
Centrifugation is used for two basic purposes:
(1) as a preparative technique to separate one type of material from others
(2) as an analytical technique to measure physical properties of macromolecules
34. - a technique for separating molecules in a mixture under the influence of an applied
electric field.
Principles:
When a mixture of proteins is applied to a gel and an electric current is applied,
smaller proteins migrate faster through the gel than do larger proteins.
The rate at which a protein moves through a gel is influenced by the gel’s pore
size and the strength of the electric field.
By suitable adjustment of these parameters, proteins of widely varying sizes
can be separated.
Types of Electrophoresis
1.SDS-Polyacrylamide Gel Electrophoresis
2.Two- Dimensional Gel Electrophoresis
37. Western Blotting (Immunoblotting)
Step 1 : After a protein mixture has been electrophoresed through an SDS gel, the separated bands are transferred
(blotted) from the gel onto a porous membrane.
Step 2 : The membrane is flooded with a solution of antibody (Ab1) specific for the desired protein. Only the band
containing this protein binds the antibody, forming a layer of antibody molecules . After sufficient time for binding, the
membrane is washed to remove unbound Ab1.
Step 3 : The membrane is incubated with a second antibody (Ab2) that binds to the bound Ab1. This second
antibody is covalently linked to alkaline phosphatase, which catalyzes a chromogenic reaction.
Step 4: Finally, the substrate is added and a deep purple precipitate forms, marking the band containing the desired
protein.
38. a) When a narrow beam of x-rays strikes
a crystal, part of it passes straight
through and the rest is scattered
(diffracted) in various directions. The
intensity of the diffracted waves is
recorded on an x-ray film or with a
solid-state electronic detector.
b) X-ray diffraction pattern for a
topoisomerase crystal collected on a
solid-state detector. From complex
analyses of patterns like this one, the
location of every atom in a protein can
be determined.