alpha-D-galactosidase from soybeans destroying blood-group B antigens. Purification by affinity chromatography and properties.
alpha-D-Galactosidase was isolated from untoasted soybean meal and purified to homogeneity by affinity chromatography on N-epsilon-aminoacaproyl alpha-D-galactopyranosylamine-Sepharose. The purified enzyme destroyed the B-specificity of human ovarian cyst B-glycoprotein with an accompanying increase in H-specificity, and converted human type-B erythrocytes to type O. The enzyme consists primarily of a tetramer, molecular weight 150 000 +/- 5 000 at pH 4.0 and of a monomer, molecular weight 40 000 +/- 3 000 at pH 8.0. Polyacrylamide gel electrophoresis in dodecyl sulfate at pH 7.2 distinguished between two types of monomeric unit of similar molecular weight. N-terminal alanine was identified as the sole N-terminal amino acid residue. The enzyme was shown to be devoid of carbohydrate.
D000017:ABO Blood-Group System; D000596:Amino Acids / Q000032:analysis; D000941:Antigens; D002846:Chromatography, Affinity; D005260:Female; D005696:Galactosidases / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D046911:Macromolecular Substances; D008970:Molecular Weight; D010048:Ovarian Cysts; D010944:Plants / Q000201:enzymology*
D000017:ABO Blood-Group System; D000596:Amino Acids; D000941:Antigens; D046911:Macromolecular Substances; D005696:Galactosidases