Aminopeptidases of the small intestinal brush border are strategically located to play a pivotal role in the assimilation of protein nutrients. but the membrane nature of these enzymes has made isolation difficult. Rat intestinal brush borders were solubilized by a papain .p-aminobenzyl cellulose complex and two aminopeptidases purified by zonal gradient centrifugation, Sephadex G-200 gel filtr...

Opioid peptides have been reported to have important functions in human reproduction. Indeed, very high concentrations of enkephalins and their degrading enzymes have been reported in human semen. In the present paper, we compare the activity of two enkephalin-degrading enzymes, aminopeptidase N and neutral endopeptidase 24.11, in different fractions of semen from normozoospermic, fertile men a...

The aminopeptidases constitute a group of enzymes with closely related activities. In clinical chemistry the analysis of the aminopeptidases and of their multiple forms in serum has for a long time been hindered by considerable confusion concerning their identification, and by a lack of characterization. This is in part due to the often large, and sometimes overlapping substrate specificities o...

We found a family with a high activity for hydrolyzing L-alanyl-beta-naphthylamide in their serum. This enzyme was confirmed to be aminopeptidase (microsomal) (EC 3.4.11.2) by means of immunological experiments involving anti-human kidney aminopeptidase (microsomal) antibody. We could not find the cause of the increased activity from the results of clinical and laboratory examinations. The enzy...

The objective of this study was to test the hypothesis that in ovo injection of carbohydrates into pigeon (Columba livia) amnion may improve the small intestine development. At d 14.5 of incubation, 80 fertile eggs were injected with 200 μL of carbohydrate solution, and 80 control eggs were not injected. The carbohydrate solution (wt/vol) contained 2.5% maltose + 2.5% sucrose, all dissolved in ...

The leucine aminopeptidase of Aeromonas proteolytica (EC 3.4.11.10) is a monomeric metalloenzyme having the capacity to bind two Zn2+ atoms in the active site. Structural information of this relatively small aminopeptidase that could illuminate the catalytic mechanism of the metal ions is lacking; hence, we have obtained sequences from the purified enzyme, cloned the corresponding gene, and ex...