title: L-Phenylalanine inhibition of muscle pyruvate kinase.
abstract: The allosteric inhibition of M1-type pyruvate kinase from rabbit skeletal muscle by phenylalanine is reciprocally dependent on Mg2+ and phosphoenolpyruvate concentrations. At pH 8, phenylalanine acts as a competitive inhibitor with respect to Mg2+ and phosphoenolpyruvate, and vice versa. Phenylalanine introduces sigmoidicity into the dependence of the reaction velocity on [Mg2+]. In vitro kinetic analysis indicates that phenylalanine inhibition of muscle pyruvate kinase is unlikely to have regulatory significance in vivo.
mesh_terms: D000494:Allosteric Regulation; D000818:Animals; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D009132:Muscles / Q000201:enzymology*; D010649:Phenylalanine / Q000494:pharmacology*; D011770:Pyruvate Kinase / Q000378:metabolism*; D011817:Rabbits
chemical_list: D010649:Phenylalanine; D011770:Pyruvate Kinase; D008274:Magnesium