Limited proteolysis of the porcine zona pellucida by homologous sperm acrosin.

Boar sperm acrosin isolated by affinity chromatography on p-(p'-aminophenoxypropoxy)benzamidine linked to Sepharose was tested for its proteolytic effect on the zona pellucida of freshly ovulated pig eggs. During 1 h in a physiological medium there was no observable change in the morphology of the zona pellucida but subsequent 125I labelling of the structure followed by electrophoretic analysis revealed that acrosin had asserted a limited and selective proteolysis.