Purification and partial characterization of hemagglutinins in seminal plasma of the sea urchin, Hemicentrotus pulcherrimus.

Two distinct hemagglutinins have been purified from seminal plasma of the sea urchin, Hemicentrotus pulcherrimus. These proteins differ in molecular weight, sugar specificity and trypsin sensitivity. Using SDS-polyacrylamide gel electrophoresis, the molecular weight of both hemagglutinins (HPSPH I and II), was estimated to be about 140 000 and 22 000, respectively. HPSPH I is a glycoprotein, the hemagglutinating activity of which is inhibited by L-arabinose, D-xylose and D-galactose when assayed for rabbit erythrocytes and inhibited by D-galactose, N-acetyl D-galactosamine, L-arabinose and D-xylose for human type A erythrocytes. Inhibitory activity of L-arabinose on agglutination of the human erythrocytes is the same as that of rabbit erythrocytes, although it is much lower than that of D-galactose and N-acetyl D-galactosamine. On the other hand, HPSPH II agglutinates only rabbit erythrocytes and caused fusion of them. Any sugar hitherto examined does not inhibit activities. Both HPSPH I and II are heat-labile and activated by Ca2+. Whereas trypsin, not alpha-chymotrypsin, destroys the former's activity, metaperiodate has not effect upon either.