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Isolation and Partial Characterization of a Glycoprotein Complex with Sperm‐Receptor Activity from Ciona intestinalis Ovary 1
Author(s) -
SANTIS ROSARIA,
PINTO MARIA ROSARIA
Publication year - 1987
Publication title -
development, growth and differentiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 66
eISSN - 1440-169X
pISSN - 0012-1592
DOI - 10.1111/j.1440-169x.1987.00617.x
Subject(s) - acrosome reaction , sperm , glycoprotein , ciona intestinalis , acrosome , biology , glycopeptide , biochemistry , receptor , glycosylation , microbiology and biotechnology , chemistry , genetics , gene , antibiotics
Sperm‐egg interaction in the ascidian Ciana intestinalis is mediated by a fucosyl‐glycoprotein (FP) component of the egg vitelline coat. FP are responsible for sperm binding, sperm activation and the acrosome reaction. In this paper we report a detailed biochemical and functional characterization of FP purified from the ovaries by affinity chromatography. thic component with sperm receptor activity is a high molecular weight glycoprotein complex (>10 7 ) with a protein‐carbohydrate ratio of 2:1, which inhibits the binding of the spermatozoa to the vitelline coat and induces sperm activation and the acrosome reaction. Exhaustive proteolytic digestion of FP yields high molecular weight glycopeptides (> 4×10 5 ), which contain N‐acetylgalactosamine, fucose, galactose and rhamnose. These glycopeptides retain some receptor activity, thus raising the question of the involvement of the polypeptide backbone in the sperm‐egg binding process. However, the glycopeptide fraction fails to induce the acrosome reaction: we suggest that the polypeptide fraction plays a role in the induction of sperm activation and the acrosome reaction.