Purification and characterization of pyruvate kinase from lamprey (Entoshenus japonicus) muscle

摘要

Pyruvate kinase from skeletal muscle of lamprey (Entosphenus japonicus), which is one of the most primitive living vertebrates, has been purified by approximately 110-fold. The isolation procedure includes chromatography on Phosphocellulose, Phenyl-5PW, and Sephacryl S-300. Sodium dodecyl sulfate gel electrohoresis shwos 59000 as the deduced subunit molecular weight and gel filtration shows 232000 as the tetrameter of the subunits. The apparent Km for phosphoenolpyruvate and ADP are 0.41 mM and 0.31 mM at pH 7.4, respectively, when the purified enzyme is saturated with the second substrate. When the enzyme is activated in the presence of frutose-1,6-diphosphate, the Km for PEP changes to 0.087 mM, and the Hill coefficient changes from 1.3 to 0.98.