Affiliation:
1. Wellcome Research Unit, Christian Medical College Hospital, Vellore 632004, Tamil Nadu, India
Abstract
1. A highly active and electrophoretically homogeneous dipeptidase was purified from the soluble extracts of monkey small-intestinal mucosa. 2. By gel-filtration studies the molecular weight of the enzyme was found to be 107000. It is composed of two identical, subunits of molecular weight 54000. 3. A paper-chromatographic method of dipeptidase assay was developed to overcome some of the difficulties encountered in the generally used spectrophotometric procedure. By using this method, the Km and k0 values of a few substrates were determined. 4. The substrate specificity of the enzyme was investigated in great detail with substrates of a wide range of possible structural types. The enzyme hydrolyses a very large proportion of the range of dipeptides tested. This enzyme, which exhibits such a wide range of action, has been termed the ‘master’ dipeptidase of the intestine. Glycylglycine, glycyl-l-proline, glycyl-l-histidine, l-prolylglycine and some of the arginine- and aspartic acid-containing dipeptides were not substrates and are possibly hydrolysed by other peptidases. These results therefore suggest that in the intestine the number of dipeptidases is rather limited. 5. In the light of these findings, the implications on the role of dipeptidases in intestinal peptide transport are discussed.
Subject
Cell Biology,Molecular Biology,Biochemistry
Cited by
62 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
1. Carnosine Dipeptidase II;Handbook of Proteolytic Enzymes;2013
2. SIZE AND SHAPE OF TWO INTESTINAL DIPEPTIDASES;International Journal of Peptide and Protein Research;2009-01-12
3. Intestinal Dipeptidases and Dipeptide Transport in the Monkey and in Man;Ciba Foundation Symposium 50 - Peptide Transport and Hydrolysis;2008-05-30
4. Protein Digestion and Absorption;Physiology of the Gastrointestinal Tract;2006
5. Why should a single nutrient—glutamine—improve outcome?;Clinical Nutrition Supplements;2004