A New Method for the Determination of γ-Glutamyltransferase in Serum

Abstract

A new, simple and sensitive method is described for assay of serum -glutamyltransferase activity based on the hydrolysis of the substrate Z,-7-glutamyl-3-carboxy-4-nitranilide which offers the advantage of producing directly its own chromogen.The substrate is highly soluble and the method can therefore easily be adapted to any equipment for the automated assay of -glutamyltransferase.The activities at measured optimum substrate concentration are slightly higher than with the Szasz ((1969), Clin.Chem.15,124-136) method in which i-glutamyl-p-nitroanilide is used as substrate. Eine neue Methode zur Bestimmung der y-Glutamyltfansferase im SerumZusammenfassung: Es wird eine einfache und empfindliche neue Methode f r die Bestimmung der -Glutamyltransferase-Aktivit t im Serum beschrieben.Sie beruht auf der Hydrolyse des Substrats Z,-7-Glutamyl-3-carboxy-4-nitranilid.Die Freisetzung von 3-Carboxy-4-nitroanilin wird kontinuierlich bei 405 nm gemessen.