Mettaloptotein

1. METALLOPROTEIN
SUBMITTED BY:
GNANASURIYAN. S
2022002053

2. INTRODUCTION -METALLOPROTEIN :
• Metalloprotein is a generic term for a protein that contains a metal
ion cofactor. A large proportion of all proteins are part of this
category. For instance, at least 1000 human proteins (out of
~20,000) contain zinc-binding protein domains. although there may
be up to 3000 human zinc metalloprotein .
• The structure of hemoglobin. The heme cofactor, containing the
metal iron, shown in green

4. ABUNDANCE :
• It is estimated that approximately half of
all proteins contain a metal. In another estimate, about
one quarter to one third of all proteins are proposed to
require metals to carry out their functions.
• Most metals in the human body are bound to proteins.
For instance, the relatively high concentration of iron in
the human body is mostly due to the iron in hemoglobin.

5. COORDINATION CHEMISTRY PRINCIPLES:
• In metalloproteins, metal ions are usually
coordinated
by nitrogen, oxygen or sulfur centers
belonging to amino acid residues of the
protein. These donor groups are often
provided by side-chains on the amino acid
residues.
• Especially important are
the imidazole substituent
in histidine residues, thiolate substituents
in cysteine residues, and carboxylate groups
provided by aspartate.

6. STORAGE AND TRANSPORT METALLOPROTEIN :
• These are the second stage product of protein hydrolysis
obtained by treatment with slightly stronger acids and
alkalies.
• OXYGEN CARRIES:
• Hemoglobin, which is the principal oxygen-carrier in
humans, has four subunits in which the iron(II) ion is
coordinated by the
planar macrocyclic ligand protoporphyrin IX (PIX) and
the imidazole nitrogen atom of a histidine residue. The
sixth coordination site contains a water molecule or
a dioxygen molecule.

7. CYTOCHROMES:
Cytochromes are redox-
active proteins containing a heme, with a
central iron (Fe) atom at its core, as
a cofactor. They are involved in electron
transport chain and redox catalysis. They
are classified according to the type of heme
and its mode of binding. Four varieties are
recognized by the International Union of
Biochemistry and Molecular
Biology (IUBMB), cytochromes
a, cytochromes b, cytochromes
c and cytochrome d.

8. RUBREDOXIN :
• Rubredoxin is an electron-carrier found in sulfur-
metabolizing bacteria and archaea. The active site contains an
iron ion coordinated by the sulfur atoms of four cysteine residues
forming an almost regular tetrahedron. Rubredoxins perform one-
electron transfer processes. The oxidation state of the iron atom
changes between the +2 and +3 states. In both oxidation states
the metal is high spin, which helps to minimize structural
changes.

9. METAL ION STORAGE AND TRANSFER :
Iron:
Iron is stored as iron(III) in ferritin. The exact nature of the binding site has not yet been
determined. The iron appears to be present as a hydrolysis product such as FeO(OH). Iron
is transported by transferrin whose binding site consists of two tyrosines, one aspartic
acid and one histidine. The human body has no mechanism for iron excretion.[citation
needed] This can lead to iron overload problems in patients treated with blood transfusions,
as, for instance, with β-thalassemia. Iron is actually excreted in urine and is also
concentrated in bile which is excreted in feces.
Calcium:
Osteopontin is involved in mineralization in the extracellular matrices of bones and
teeth.

10. • Signal transduction metalloprotein :
• Calmodulin:
• Calmodulin is an example of a signal-transduction protein. It is a small protein that
contains four EF-hand motifs, each of which is able to bind a Ca2+ ion.

11. REFERENCE :
• www.slideshare.com
• https://en.m.wikipedia.org/wiki/Metalloprotein
• https://www.google.com/imgres?imgurl=https://image.slidesharecdn.com/metalloprotein
sgbk-220621085305-3abcd449/85/metalloproteins-pptx-5-
320.jpg?cb%3D1667971678&imgrefurl=https://www.slideshare.net/9659281515/metallopr
oteins-pptx&docid=B-vBpKf8m637HM&tbnid=dTIAfUDYPC8IuM&vet=1&source=sh/x/im/4
• Introduction to Agricultural Biochemistry
• Agricultural Biochemistry at Glance