A new endo-beta-galactosidase releasing Gal alpha 1----3Gal from carbohydrate moieties of glycoproteins and from a glycolipid.

Culture fluid of Clostridium perfringens contained an endoglycosidase releasing a galactosyl disaccharide from glycans derived from glycoproteins of teratocarcinoma OTT6050. The endoglycosidase was purified by ammonium sulfate precipitation, Sephadex G-200 column chromatography, and DEAE-Sephadex A-25 column chromatography. The structure of the disaccharide product was determined to be Gal alpha 1----3Gal. The enzyme also released the disaccharide from bovine thyroglobulin glycopeptide and from a pentaglycosyl ceramide (Gal alpha 1----3Gal beta 1----4GlcNAc beta 1----3Gal beta 1----4Glc-Cer). Therefore, we concluded that the enzyme was an endo-beta-galactosidase cleaving Gal beta 1----4GlcNAc linkage. Keratan sulfate and the antigenic determinant of blood group type B were resistant to the enzyme: the specificity of the enzyme is different from other endo-beta-galactosidases so far described. The enzyme could act on intact thyroglobulin and defucosylated ovarian cyst mucin.