title: Creatine phosphate inhibition of heart lactate dehydrogenase and muscle pyruvate kinase is due to a contaminant.
abstract: Previously reported inhibitions of heart lactate dehydrogenase (Guppy, M., and Hochachka, P.W. (1978) J. Biol. Chem. 253, 8465-8469) and muscle pyruvate kinase (Kemp, R.G. (1973) J. Biol. Chem. 248, 3963-3967) by creatine phosphate are due to oxalate which is a contaminant found in some commercial preparations of creatine phosphate.
mesh_terms: D000818:Animals; D002417:Cattle; D007770:L-Lactate Dehydrogenase / Q000037:antagonists & inhibitors*; D009132:Muscles / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology; D010070:Oxalates / Q000494:pharmacology*; D010725:Phosphocreatine / Q000494:pharmacology*; D011770:Pyruvate Kinase / Q000037:antagonists & inhibitors*; D011817:Rabbits
chemical_list: D010070:Oxalates; D010725:Phosphocreatine; D007770:L-Lactate Dehydrogenase; D011770:Pyruvate Kinase