title: The measurement of gamma-glutamyl hydrolase (conjugase) activity in rat brain.
abstract: An assay using the artificial substrate, 2,4-diamino-10-methyl-pteroylglutamyl-gamma-glutamate (MTX-G1), was developed to measure gamma-glutamyl hydrolase (conjugase), which hydrolyzes folylpolyglutamates. This assay allows us to: 1) measure conjugase for the first time in rat brain and 2) measure conjugase in a reliable, sensitive and inexpensive manner. The MTX-binding assay results were compared to samples analyzed by HPLC and found to vary by only 13%. The artificial substrate, MTX-G1, had a lower rate of hydrolysis than pteroylglutamyl-gamma-glutamate (Pte-G2), 70.7 +/- 0.64 and 92.6 +/- 0.22 nmoles/hr/mg protein respectively. Conjugase was semi-purified 24 fold in H2O and found to have a pH optimum of 5.0.
authors: Dept. of Neurology, Stanford University, CA 94305.
authors: D M
authors: DM
authors: Hartley
authors: S R
authors: SR
authors: Snodgrass
authors: P A
authors: PA
authors: Bradshaw
mesh_terms: D000818:Animals; D001921:Brain / Q000201:enzymology*; D002851:Chromatography, High Pressure Liquid; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008297:Male; D051381:Rats; D011623:gamma-Glutamyl Hydrolase / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D011623:gamma-Glutamyl Hydrolase; D003546:Cysteine Endopeptidases