The pyruvate kinase isoenzyme type M1 is expressed in tissues which are strongly dependent upon a high rate of energy regeneration, i.e. muscle and brain. Among the pyruvate kinase isoenzymes, M1-PK has the highest affinity to its substrate phosphoenolpyruvate and is not alosterically regulated. The M1 and M2-PK isoenzymes are encoded by the same gene but result from alternative splicing of exons 9 and 10. The human M1 and M2-PK isoenzyme differ in 23 amino acids wthin a stretch of 56 amino acids. Pyruvate kinase type M2: amino acid sequence Pyruvate kinase isoenzymes: M2-PK |
