Isolation of a Flavin-Protein Compound from Milk

Abstract

WE have been able to prepare a flavin-protein compound from cow's milk by the following procedure: (1) half-saturation with ammonium sulphate of the whey of rennin-treated milk ; (2) ether extraction of the dried precipitate ; (3) reprecipitation by 33 per cent saturation of the solution of the re-dissolved precipitate with ammonium sulphate at pH. 4.0 and 0°; (4) elimination of the fraction insoluble in 25 per cent saturated ammonium sulphate at pH. 4.0 and in presence of 10 per cent alcohol ; (5) adsorption on and elution from alumina cγ¹followed by ultrafiltration and further fractionation with ammonium sulphate.