Creatine kinase isoenzymes play a central role in energy transduction in tissues with large, fluctuating energy demands, such as skeletal muscle, heart, brain and spermatozoa. The CKM isoform, predominant in skeletal muscle and heart tissue, is a cytoplasmic enzyme involved in energy homeostasis and is an important serum marker for myocardial infarction. CKM reversibly catalyzes the transfer of phosphate between ATP and various phosphogens such as creatine phosphate. It acts as a homodimer in striated muscle as well as in other tissues, and as a heterodimer with a similar brain isozyme in heart. The encoded protein is a member of the ATP:guanido phosphotransferase protein family.

HUMAN

2-8°C (short-term); -20°C (long-term)