Myoglobin Protein (Active)

Myoglobin, MB is an iron- and oxygen-binding protein found in the muscle tissue of vertebrates in general and in almost all mammals. It is a cytoplasmic hemoprotein, expressed solely in cardiac myocytes and oxidative skeletal muscle fibers, that reversibly binds O2 by its heme residue, a porphyrin ring:iron ion complex. MB is a single-chain globular protein of 153 or 154 amino acids, containing a heme prosthetic group in the center around which the remaining apoprotein folds. Myoglobin is released from damaged muscle tissue (rhabdomyolysis), which has very high concentrations of myoglobin. The released myoglobin is filtered by the kidneys but is toxic to the renal tubular epithelium and so may cause acute renal failure. It is a sensitive marker for muscle injury, making it a potential marker for heart attack in patients with chest pain. However, elevated myoglobin has low specificity for acute myocardial infarction (AMI) and thus CK-MB, cTnT, ECG, and clinical signs should be taken into account to make the diagnosis.

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