Isolation and partial characterization of proteoglycans from rice bran

Extraction of rice bran with hot water, followed by removal of protein and starch, yielded a proteoglycan. Successive fractionation of this proteoglycan by salting out with ammonium sulfate and by DEAE-Sephadex column chromatography yielded several fractions shown to be homogeneous by disc electrophoresis. Treatment of the fractions with alkali and a proteolytic enzyme has shown that the polysaccharide and protein of the proteoglycan are most probably linked through an O-glycosyl linkage through hydroxyproline.