Purification of the Mr 80,000 and Mr 210,000 proteins of the sea urchin sperm plasma membrane. Evidence that the Mr 210,000 protein interacts with egg jelly.
Two immunologically cross-reactive plasma membrane proteins, of Mr 80,000 and Mr 210,000, have been purified to apparent homogeneity from sperm of the sea urchin Strongylocentrotus purpuratus. Purification includes a combination of antibody and wheat germ agglutinin affinity chromatography. The two proteins have similar but not identical amino acid compositions; however, their carbohydrate composition differs substantially. After purification, the Mr 210,000 protein binds to both living eggs and isolated egg jelly in a species-specific manner, but the Mr 80,000 protein does not. The inactivity of the Mr 80,000 protein could be due to denaturation during purification. The data are consistent with a model in which the Mr 210,000 protein acts as a jelly receptor in the sperm membrane, promoting the ion movements necessary to initiate the sperm acrosome reaction.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D002462:Cell Membrane / Q000032:analysis; D002846:Chromatography, Affinity; D005260:Female; D008297:Male; D008565:Membrane Proteins / Q000302:isolation & purification*; D008970:Molecular Weight; D012617:Sea Urchins; D013045:Species Specificity; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000648:ultrastructure*
D000596:Amino Acids; D002241:Carbohydrates; D008565:Membrane Proteins