A simplified method for purification of an antitumor acidic glycoprotein from Streptococcus pyogenes (Su strain) by...

A simplified method for purification of an antitumor acidic glycoprotein (SAGP) from Streptococcus pyogenes (Su strain) by immunoaffinity chromatography is described. A cell-free crude extract prepared from the cocci was applied to the anti-SAGP IgG coupled Sepharose column, and elution was conducted with an alkaline buffer. The material eluted was confirmed to be homogeneous and identical with SAGP as demonstrated by both relative mobility on the SDS-polyacrylamide gel column and the antigenicity on the double diffusion agar plate. The cell-growth inhibitory activity of SAGP prepared by the present method was almost the same as that of SAGP purified by the previous time-consuming method. Since this simplified method provides a higher yield of SAGP, it will be useful in further studies on the biological properties of SAGP.