ISOLATION AND PURIFICATION OF COLOSTROKININ FROM BOVINE COLOSTRUM

It was confirmed that a biologically active substance was released when pretreated bovine colostrum (colostrokininogen) was incubated with human salivary kallikrein. It was also demonstrated that colostrokininogen belongs to the immunolactoglobulin of colostric proteins. Crude colostrokinin was purified by means of adsorption on carboxymethylcellulose, Sephadex gel filtration (G-25, G-10 and G-15) and CM-Sephadex column chromatography. The active fraction obtained after CM-Sephadex column chromatography is homogeneous in thin-layer chromatography (TLC) and paper electrophoresis. The peptide spot and biological activity migrated similarly in paper electrophoresis. The vasodilator activity of 1 mg colostrokinin in dogs corresponds to that of 258 μg bradykinin. The pharmacological activities of colostrokinin qualitatively agreed with those of kinins, such as bradykinin. Vasodilation in dogs, stimulation of smooth muscle of rats, and increase in capillary permeability in guinea pigs were caused by colostrokinin. Finally, it was indicated that colostrokinin might aid in the transport of high molecular weight substances across the neonatal gut of ungulates. © 1969.