Rana catesbiana卵から生物学的性質の異なる二種の凝集素の分離

抄録

Eggs of Rana catesbiana were found to contain two agglutinins showing specific reactivities, one with human blood group A erythrocytes and the other with mouse Ehrlich ascites carcinoma cells and rat ascites hepatoma cells (AH-109A). These agglutinins were purified by chromatography over Sephadex G-75, DEAE- and CM-cellulose, and finally hydroxylapatite column. The purified anti-A agglutinin contained about 1.6% carbohydrate and the molecular weight estimated by polyacrylamide gel electrophoresis in sodium dodecyl sulfate was 17000. The purified cancer cell agglutinin contained about 0.6% carbohydrate and the molecular weight was 15000. Its electrophoretic mobility on cellulose acetate membrane was similar to that of basic proteins such as protamine and histone. Two agglutinins had similar amino acid compositions, and showed a relatively large amount of glutamic acid and aspartic acid but a small amount of lysine, arginine, and histidine. The agglutinating activity of anti-A agglutinin is inhibited by oligosaccharides such as lactose and N-acetyllactosamine, whereas that of cancer cell agglutinin is specifically inhibited only by ganglioside obtained from human blood group A erythrocytes. The remarkable difference in the biological properties of these agglutinins are discussed.