title: Sperm glycosidase as a plausible mediator of sperm binding to the vitelline envelope in Ascidians.
abstract: In the Ascidian, Ciona intestinalis, sperm alpha-L-fucosidase is concluded to be a recognition protein for the sperm receptor in the vitelline envelope. The spermatozoa bind to the vitelline envelope probably by forming rather stable substrate (alpha-L-fucoside)-enzyme complex at many spots. Experimental evidence indicates a good correspondence in the properties between receptor binding activity and alpha-L-fucosidase activity such as the effects of saccharides, of pH and of monoclonal antibodies raised against sperm alpha-L-fucosidase, and locus in the sperm. A general mechanism involving an enzyme as a recognition protein for the cell to cell binding is also discussed in relation to the molecular evolution of the recognition proteins.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D001665:Binding Sites; D005260:Female; D008297:Male; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000201:enzymology*; D014561:Urochordata / Q000502:physiology; D014817:Vitelline Membrane / Q000502:physiology; D005644:alpha-L-Fucosidase / Q000276:immunology / Q000502:physiology*
chemical_list: D000911:Antibodies, Monoclonal; D005644:alpha-L-Fucosidase