Glycyl-l-leucine hydrolase, a versatile ‘master’ dipeptidase from monkey small intestine

A comparative study of the distribution of soluble and particulate glycyl-L-leucine hydrolase in the small intestine.

1. A comparative study has been made of glycyl-L-leucine hydrolase activity in the soluble and particulate fractions of intestinal mucosa from monkey, guinea-pig, rabbit and rat. The specific activity of the soluble enzyme is very high in monkey and guineapig, and lower in rabbit and rat. The particulate enzymes from all the four species show low specific activities and form l-lO% of the total ...

Substrate specificity of a highly active dipeptidase purified from monkey small intestine.

Interaction of amino acids with glycl-L-leucine hydrolysis and transport in monkey small intestine.

1. There are two saturable transport processes in the monkey small intestine for glycyl-L-leucine, one with Vmax. 1 mumol min-1 g-1 wet weight of tissue and an affinity constant (kt) of 5 mmol/l, and the other with Vmax 3.9 mumol min-1 g-1 wet weight of tissue and kt 33 mmol/l. 2. Glycyl-L-leucine uptake is inhibited by a wide variety of amino acids, although to a variable extent. The inhibitio...

Development of a radiochemical assay for glycyl-leucine dipeptidase in human B- and T-lymphocytes.

Recent technical advances in the isolation of human lymphocytes have made it possible to obtain preparations enriched in Bor T-cells (Wybran, 1973; Pellegrino et al., 1976). This in turn facilitates studies on the comparative enzymology of Band T-lymphocytes, which may be relevant to some leukaemic states. Studies on lysosomal enzymes, including acid phosphatase, /3-glucuronidase (Meusers et al...

Studies on a wide-spectrum intestinal dipeptide uptake system in the monkey and in the human.

1. The intestinal transport of glycine and leucine residues of glycyl-L-leucine was studied in the monkey and in the human in vitro. Uptake of both [14C]glycyl-L-leuine and glycyl-L-[14C]leucine show similar Kt values, but there is a marked difference in the Vmax. values. Preliminary studies suggest that this anomalous difference in the Vmax. values may be due to the greater efflux rate of glyc...