Analysis for Transaminases in Serum with an Amperometric Glutamate Electrode

Glutamate oxidase (EC1.4.3.7) fromStreptomyces sp.aslyophilized powder was purchased from YamasaShoyu Co.,Tokyo, Japan. L-Aspartate aminotransferase(AST; EC2.6.1.1) andL-alanine aminotransferase (ALT;EC2.6.1.2) frompigheart were purchased from SigmaChemical Co., St. Louis, MO, aswere L-glutamate,L-aspartate, L-alarnne, and a-ketoglutarate. Allotherreagents were analytical reagent grade from C.Erba,Milan, Italy.Cellulose acetate membrane, lOO-Da cutoff, wasmadeinourlaboratory asdescribed intheliterature (7).Poly-carbonate membrane, 0.03-j.i.m poresize,wasfromNude-pore, Pleasanton, CA. Immobilon AV immunoaffinitymembrane was