Isolation,purification,and chemical composition of sanguicin from Streptococcus sanguis

Objective:To isolate and purify sanguicin from Streptococcus sanguis and determine its chemical composition.Methods:Sanguicin was obtained from the culture supernatant by using hydroxylapatite column chromatography,Sephadex G-150 gel chromatography,and ultra-filtration.The purity,molecular weight,and subunit molecular weight of sanguicin were determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis.The proportions of protein and saccharide were determined by ultraviolet absorption technique and phenol-sulfuric acid method,respectively.Results:The molecular weight of sanguicin was 180 kDa,and the molecular weights of 2 subunits of sanguicin were 110 and 70 kDa,respectively.The proportions of protein and saccharide were 87.51% and 12.49%.Conclusion:Sanguicin from Streptococcus sanguis is a glycoprotein which consists of 2 subunits.