Sperm plasma-membrane-associated glutathione S-transferases as gamete recognition molecules.

摘要: Glutathione S-transferases (GSTs) are enzymes that detoxify electrophilic compounds. Earlier studies from our laboratory showed anti-GST antibodies interfered with the fertilising ability of spermatozoa Capra hircus (goat) in vitro, suggesting GSTs localised at cell surface. In this study, we provide evidence for presence 24 kDa on sperm plasma membrane attached by non-covalent interactions. The GST activity associated spermatozoal was significantly higher than present membranes brain cells, hepatocytes, spleenocytes and ventriculocytes. Analysis isoforms demonstrates Pi Mu membranes. Both were able to bind solubilised as well intact zona pellucida (ZP) through their N-terminal regions but failed ZP once oocytes fertilised. Solubilised goat separates into three components, one which, ZP3-like component, bound GSTs. High concentrations or led aggregation GSTs, resulting release acrosin. contrast, inhibition binding ZP, saturation sites using peptides designed N-terminii blocking raised against peptides, inhibited essential prefertilisation changes sperm. These data therefore demonstrate strategic location catalytically active defensive surface also act zona-binding proteins. Therefore, sperm-surface serve bifunctional molecules a transcriptionally inactive whose requirement cellular defense economy it can carry is greater any somatic type.