From Freepedia
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protein type:
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Hemoprotein
<tr><td bgcolor=#e7dcc3 width=85>Functions:
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oxygen storage/transport
<tr><td bgcolor=#e7dcc3 width=85>Domains:
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globin
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Diseases:
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kidney disease,
vasospasm
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Taxa expressing:
<td style="border-top:1px solid #e7dcc3" width=220>many
metazoan phyla,
Archaea?,
protozoan/eubacterial?
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Cell types:
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muscle cells
<tr><td bgcolor=#e7dcc3 width=85>Subcellular localization:
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cytoplasm
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covalent modifications
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glycation?,
phosphorylation in
whales?
<tr><td bgcolor=#e7dcc3 width=85>Other names:
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myoglobin-like proteins in
microorganisms
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Molecular interactions
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oxygen,
heme,
carbon monoxide,
nitric oxide
<tr><td bgcolor=#e7dcc3 width=85>related articles:
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X-ray crystallography,
Secondary structure
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Myoglobin is a
single-chain protein of 153
amino acids, containing a
heme (
iron-containing
porphyrin) group in the center. With a molecular weight of 16,700
Daltons, it is the primary
oxygen-carrying
pigment of
muscle tissues. Unlike the blood-borne
hemoglobin, to which it is structurally related, this protein does not exhibit
cooperative binding of oxygen. Instead, the binding of oxygen by myoglobin is unaffected by the oxygen tension in the surrounding tissue. In
1957,
John Kendrew and associates successfully determined the structure of myoglobin by high-resolution
X-ray crystallography.
For this discovery, John Kendrew shared the 1962 Nobel Prize in chemistry with Max Perutz.
Role in disease
Myoglobin is the putative protein that causes acute renal failure in rapid breakdown of muscle (e.g. rhabdomyolysis, severe crush trauma, malignant hyperthermia, status epilepticus and neuroleptic malignant syndrome), due to its toxicity to renal tubular epithelium.
Myoglobin is a sensitive marker for muscle injury, making it a potential marker for myocardial infarction in patients with chest pain. Its specificity and the cost of the analysis has prevented its widespread use.
See also
External links
