Amperometric Assay of .GAMMA.-Glutamyltransferase Using Glutathione as a Substrate.

Gamma-glutamyltransferase: Substrate inhibition, kinetic mechanism, and assay conditions.

Gamma-glutamyltransferase activity in serum is shown to be competitively inhibited by the two substrates gamma-glutamyl-4-nitroanilide and glycylglycine. Awareness of this is of importance when one is choosing final reaction conditions for the assay of the enzyme. Gamma-glutamyltransferase probably acts by a "ping-pong bi-bi" kinetic mechanism, which fits with the double competitive substrate i...

Gamma-glutamyltransferase as a cardiovascular risk factor.

The association of a novel factor with clinical vascular disease must meet the same high standard met by ‘traditional’ risk factors. Serum gamma-glutamyltransferase (GGT) activity is a low-cost, highly sensitive laboratory test: though it is currently considered as an index of hepatobiliary dysfunction and alcohol abuse, pathology studies from our group since 1998 have indicated its possible ro...

A rapid assay for the quantitation of gamma-glutamyl hydrolase using a fluorogenic peptide as substrate.

Donor substrate specificity of bovine kidney gamma-glutamyltransferase.

The enzyme γ-glutamyltransferase (GGT) catalyzes the hydrolysis of the γ-glutamyl isopeptide bond of glutathione conjugates (donor substrates), releasing glutamic acid, or the transfer of the donor's γ-glutamyl group to an acceptor substrate, such as a dipeptide. The specificity of GGT for xenobiotic donor substrates has not been fully characterized. The transpeptidation activity of bovine kidn...

Is serum gamma-glutamyltransferase a biomarker of xenobiotics, which are conjugated by glutathione?

A meta-analysis of 10 prospective cohort studies,1 including our own,2 reported that serum -glutamyltransferase (GGT) predicted incident vascular events. This metaanalysis posed one important, but unsolved question: why does serum GGT predict incident vascular events? In addition to vascular events, serum GGT predicts various important clinical outcomes including type 2 diabetes, metabolic synd...