Localization of gamma-glutamyl transferase on polyacrylamide gels using L-gamma-glutamyl-p-nitroanilide as substrate.

A method has been developed for the localization of gamma-glutamyltransferase (gamma-GT) on polyacrylamide gels using L-gamma-glutamyl-p-nitroanilide as substrate. The optimum conditions for staining on polyacrylamide gels with this substrate were evaluated and compared with the staining method using N-gamma-L-glutamyl-alpha-naphthylamide as substrate. Using papain digested, purified gamma-GT from human fetal liver it was shown that the method could be used for quantitation of the enzyme on polyacrylamide gels. It was also shown that identical patterns of staining for serum gamma-GT could be obtained with L-gamma-glutamyl-p-nitroanilide and N-gamma-L-glutamyl-alpha-naphthylamide as substrate.