Optimized determination of γ glutamyltransferase by reaction rate analysis

Abstract

A method is described for measuring γ glutamyltransferase (EC 2.3.2.2) activity in serum, which can be used with automated enzyme analyzers (such as the LKB 8600 Reaction Rate Analyzer) that require enzyme reactions to be initiated with substrate. The method also permits optimal determination conditions to be obtained at 37°C. The enzymatic reaction is commenced by adding γ glutamyl p nitroanilide dissolved in dilute hydrochloric acid to samples preincubated with tris (hydroxymethyl)aminomethane glycylglycine buffer. The p nitroaniline liberated is continously monitored at 37°C at 405 nm. The pH of the preincubation buffer is such that the optimal pH for the enzyme reaction results from addition of the acid substrate solution.