Open AccessEgg surface glycoprotein receptor for sea urchin sperm bindin.
Author(s) -
Charles G. Glabe,
Victor D. Vacquier
Publication year - 1978
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.75.2.881
Subject(s) - sea urchin , glycoprotein , sperm , receptor , biochemistry , biology , isoelectric point , chemistry , trypsin , botany , microbiology and biotechnology , enzyme
Bindin is an insoluble protein coating the sperm acrosome process and mediating the adhesion of sperm to sea urchin eggs. Milligrams of bindin have been isolated. Here we report the identification, isolation, and partial characterization of a high molecular weight, trypsin-sensitive glycoprotein fraction from the sea urchin egg surface having species-specific affinity for bindin. This glycoprotein may be the egg surface receptor for bindin. The bindin receptor was released from 125-I-labeled eggs by parthenogenetic activation of eggs with ionophore A23187 in the presence of soybean trypsin inhibitor. The receptor has an isoelectric point of 4.02 and a molecular weight in sea water greater than or equal to 5 X 10(6), suggesting that it is an aggregate. It contains 34% neutral sugars, which are galactose and mannose.