Variation of human intestinal gamma-glutamyl transpeptidase in ontogenetic development.
Activity of gamma-glutamyl transpeptidase in human intestines was measured against alpha-naphthylamide and 12 gamma-glutamyl amino acids and peptides as substrate. Distinctly altered activity was found to accompany ontogenetic development. The ratio of the transpeptidase activity tested against monoglutamyl substrates in the intestines of 7-month fetuses, newborns and adults was 15:1:4, whereas the ratio of gamma-glutamyl cyclotransferase activities in the same age groups was 1-0:1-2:1-6. Distinct differences were found in resistance to heating, sensitivity to L-serine plus borate, and other effectors, and electrophoretic mobility, between fetal gamma-glutamyl transpeptidase and the enzyme from adults, which supports the hypothesis of existence of two forms of the enzyme in the human intestines. The results suggest involvement of gamma-glutamyl transpeptidase in the pathomechanism of celiakia in children.
D000293:Adolescent; D000328:Adult; D001881:Borates / Q000494:pharmacology; D004587:Electrophoresis, Agar Gel; D005260:Female; D005333:Fetus / Q000201:enzymology; D006358:Hot Temperature; D006801:Humans; D007413:Intestinal Mucosa / Q000201:enzymology; D007421:Intestine, Small / Q000201:enzymology; D007422:Intestines / Q000201:enzymology*; D008297:Male; D009439:Neuraminidase / Q000494:pharmacology; D011247:Pregnancy; D012694:Serine / Q000494:pharmacology; D005723:gamma-Glutamyltransferase
D001881:Borates; D012694:Serine; D005723:gamma-Glutamyltransferase; D009439:Neuraminidase