title: Glutamine transaminase from brain tissue. Further studies on kinetic properties and specificity of the enzyme.
abstract: Glutamine transaminase, highly purified from rat brain, was studied. In the first series of experiments, the kinetics of the transamination reaction between 2-oxoglutaramate and phenylalanine were examined in order to determine the type of reaction mechanism. This proved to be of the ping-pont type, as can be expected for a transamination. The specificity of the enzyme for various amino acids and 2-oxo acids was then studied in detail. The most active substrates were glutamine, methionine and ethionine as amino-group donors, and phenylpyruvate, glyoxalate and 2-oxo-4-methiobutyrate as amino-group acceptors. For these and several other substrates, the kinetic constants, V and Km, were determined.
mesh_terms: D000596:Amino Acids; D000818:Animals; D001921:Brain / Q000201:enzymology*; D005973:Glutamine; D007656:Ketoglutaric Acids / Q000494:pharmacology; D007700:Kinetics; D008433:Mathematics; D010649:Phenylalanine / Q000494:pharmacology; D051381:Rats; D013329:Structure-Activity Relationship; D000637:Transaminases / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D007656:Ketoglutaric Acids; D005973:Glutamine; D010649:Phenylalanine; D000637:Transaminases