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[1]. Unlike the blood-borne hemoglobin, to which it is structurally related[2], this protein does not exhibit cooperative binding of oxygen. Instead, the binding of oxygen by myoglobin is unaffected by the oxygen pressure in the surrounding tissue. In 1957, John Kendrew and associates successfully determined the structure of myoglobin by high-resolution X-ray crystallography[3].
For this discovery, John Kendrew shared the 1962 Nobel Prize in chemistry with Max Perutz[4].
Role in disease
Myoglobin has been implicated as a cause of acute renal failure following damage to muscle tissue (e.g. rhabdomyolysis, severe crush trauma, malignant hyperthermia, status epilepticus and neuroleptic malignant syndrome), due to its toxicity to renal tubular epithelium[5].
Myoglobin is a sensitive marker for muscle injury, making it a potential marker for myocardial infarction in patients with chest pain[6]. Its specificity and the cost of the analysis has prevented its widespread use.
During muscle death due to infarction, myoglobin is released, which is toxic to the kidneys. If it is misdiagnosed, it can cause much worse conditions, such as cardiac arrest or even worse.
References
- ^ George A. Ordway and Daniel J. Garry (2004). "Myoglobin: an essential hemoprotein in striated muscle". Journal of Experimental Biology 207: pages 3441–3446. DOI:10.1242/jeb.01172.
- ^ Harvey Lodish, Arnold Berk, Lawrence S. Zipursky, Paul Matsudaira, David Baltimore and James Darnell (2000). “Evolutionary tree showing the globin protein family members myoglobin and hemoglobin” Molecular Cell Biology, Fourth Edition, W. H. FREEMAN. ISBN 0-7167-3136-3.
- ^ Oxy-myoglobin at 0.1 nm resolution: PDB 1A6M. Sperm whale myoglobin at 0.17 nm resolution: PDB 1VXH.
- ^ The Nobel Prize in Chemistry 1962
- ^ Toshio Naka, Daryl Jones, Ian Baldwin, Nigel Fealy, Samantha Bates, Hermann Goehl, Stanislao Morgera, Hans H. Neumayer and Rinaldo Bellomo (2005). "Myoglobin clearance by super high-flux hemofiltration in a case of severe rhabdomyolysis: a case report". Critical Care 9: pages R90–R95. DOI:10.1186/cc3034.
- ^ M. Weber, M. Rau, K. Madlener, A. Elsaesser, D. Bankovic, V. Mitrovic and C. Hamm (2005). "Diagnostic utility of new immunoassays for the cardiac markers cTnI, myoglobin and CK-MB mass". Clinical Biochemistry 38: pages 1027–1030. Entrez PubMed 16125162.
See also
