The measurement of gamma-glutamyl hydrolase (conjugase) activity in rat brain.
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.
Hartley
D M
DM
Dept. of Neurology, Stanford University, CA 94305.
Snodgrass
S R
SR
Bradshaw
P A
PA
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*
D011623:gamma-Glutamyl Hydrolase; D003546:Cysteine Endopeptidases