title: A new assay method of gamma-glutamyltransferase with 4-aminobenzoate hydroxylase from Agaricus bisporus as a coupling enzyme.
abstract: We have developed a new ultraviolet spectrophotometric method for measurement of serum gamma-glutamyltransferase activity. The principle of the method is as follows. Using L-gamma-glutamyl-3-chloro-4-aminobenzoate as the donor substrate, 3-chloro-4-aminobenzoate formed upon transfer of the gamma-glutamyl moiety from the donor substrate to the acceptor substrate glycylglycine is stoichiometrically converted to 3-chloro-4-hydroxyaniline by 4-aminobenzoate hydroxylase from Agaricus bisporus, coupled with the oxidation of NADH to NAD+, and the resulting decrease in absorbance at 340 nm is monitored. The results obtained indicate that there is a good possibility to establish an ultraviolet spectrophotometric method for measurement of serum gamma-glutamyltransferase activity using L-gamma-glutamyl-3-chloro-4-aminobenzoate as the donor substrate and 4-aminobenzoate hydroxylase from Agaricus bisporus as a coupling enzyme.
authors.affiliation: Department of Chemistry, College of Science & Engineering, Aoyama Gakuin University, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Mizutani
authors.forename: Y
authors.initials: Y
authors.lastname: Nakano
authors.forename: S
authors.initials: S
authors.lastname: Yamada
authors.forename: T
authors.initials: T
authors.lastname: Samejima
mesh_terms: D000364:Agaricus / Q000201:enzymology*; D002846:Chromatography, Affinity / Q000379:methods*; D002850:Chromatography, Gel / Q000379:methods*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D006899:Mixed Function Oxygenases / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D005723:gamma-Glutamyltransferase / Q000097:blood*
chemical_list: D006899:Mixed Function Oxygenases; C050092:4-aminobenzoate hydroxylase; D005723:gamma-Glutamyltransferase