Hyaluronidase PH-20 (SPAM1)

Involved in sperm-egg adhesion. Upon fertilization sperm must first penetrate a layer of cumulus cells that surrounds the egg prior to reaching the zona pellucida.

The cumulus cells are embedded in a matrix containing hyaluronic acid that is formed prior to ovulation. This protein aids in penetrating the layer of cumulus cells by digesting hyaluronic acid.