Purification of Bovine Bradykininogen

Abstract

The protein precursor of bradykinin and kallidin has been purified from bovine blood. The purification procedure, which has good reproducibility, consisted of fractionation with ammonium sulfate, heat treatment, chro-matography on DEAE-cellulose, pH treatment and chromatography on CM-cellulose. The average yield of bradykininogen was about 100 mg. dry weight from 8 liters of bovine blood. Ultracentrifugation and moving bound-ary electrophoresis of the purified bradykini-nogen showed a nearly homogeneous single peak. Trypsin, venom enzyme and hog pan-creatic kallikrein acted on the purified brady-kininogen and released contractile materials for the guinea pig ileum. These active mate-rials formed enzymatically have been identified as bradykinin in the case of trypsin or venom enzyme, and as kallidin in the case of kalli-krein.
We are greatly indebted to Dr. D. F. Elliott of National Institute for Medical Research, Mill Hill, London, for the valuable sample of synthetic brady-kinin. We are further obliged to Dr. S. Matushima of Teikoku Hormone Manufacturing Co., Tokyo, for kallikrein and to Dr. Y. Kawade for the ultracentri-fugal examinations.