Sciencemadness Discussion Board

chemical contraceptives

xxxxx - 19-5-2007 at 08:14

there is a chemical which enables the sperm to locate the egg. i believe it is something like undecanal. however there is another chemical, this is released when a sperm enters the egg which causes the egg to develop a hard exterior shell which does not allow any other sperm to enter the egg. i was wondering if this chemical has been identified and if there was any research regarding using this as a method of contraception.

Pyridinium - 19-6-2007 at 22:27

I believe the adhesion of the two cell types is facilitated by one of the lectins, a class of cell adhesion proteins. Specifically I think it is oligosaccharides that bind to the lectin and allow the binding-recognition. A lot of this sort of cell signaling / adhesion is dependent on these protein-saccharide interactions.

I don't know offhand what the glycoprotein is that makes the egg cell surface change after binding of one sperm cell, but it's probably changed by a neuraminidase or some other enzyme that removes or adds certain saccharides from the chains.

Sulfate groups can also play a role in binding.