Effects of 'casoparan', a peptide isolated from casein hydrolysates with mastoparan-like properties

Abstract

CASEIN, a protein found in milk of several species, is divided into different chains from 19 to 25 kDa. Casein is also considered as a source of amino acids and generating peptides with biological activities such as opiate, immunostimulating, antibacterial, peptidase inhibitors, among others.In this work, Sephadex G-10 chromatography followed by high-performance liquid chromatography isolation purified NZCase TT, an industrial culture media for tetanus toxin production. In the first step, four pools were isolated and tested in different assays: isolated smooth muscle assay (guinea pig ileum, rat uterus), phagocytosis in vitro of opsonized sheep red blood cells, and hydrogen peroxide (H₂O₂) release from mouse peritoneal macrophages.Pool III was the main active pool being able to potentiate bradykinin action in guinea pig ileum, stimulating phagocitic activity by resident macrophages and increasing H₂O₂ release from macrophages previously activated with bacille Calmette Guérin.Using mass spectra the primary structure of the main peptide from pool III was obtained – INKKI, which corresponds to β-casein fragment 26-30.The immunostimulating action is probably related to a direct action in macrophage cells.