Generation of a Xenopsin-immunoreactive peptide by pepsinization of bovine milk

Abstract

This study was carried out to examine the possible generation of a Xenopsin immunoreactive peptide by pepsinisation of bovine milk. Bovine milk, trypsinised and pepsinised bovine milk, were all assayed for Xenopsin immunoreactivity (XP-IR). XP-IR was present only in pepsinised bovine milk Analysis of pepsinised bovine milk by gel permeation chromatography and high performance liquid chromatography, both resolved a single peak of immunoreactivity with identical chromatographic characteristic to synthetic Xenopsin. These data indicate the generation of a Xenopsin immunoreactive peptide by the action of pepsin on a putative precursor(s), present in bovine milk. The acidic environment of the gastric lumen provides the suitable conditions required for this process. It is possible that this peptide, thus generated, might play a part in the switching off of the gastric induced gastric acid release which occurs in the stomach and also in the release of antral gastrin and pancreatic peptides, glucagon, insulin and pancreatic polypeptide. These two mechanisms are of great significance in the infant whose sole diet consists of milk.

Key Words: Xenopsin,pepsinisation, bovine milk.


(Global Journal of Pure and Applied Sciences: 2002 8(4): 441-446)