Coupling of a proton pump with superoxide radical-superoxide dismutase system in maturing mammalian spermatozoa and its association with sperm motility.

Mammalian spermatozoa possess a membrane-located 'proton pump' which appears to regulate the acquisition and maintenance of their motility. The 'proton pump' seems to be coupled with the superoxide radical-superoxide dismutase system which, when uncoupled, results in total loss of sperm motility. Addition of sulfhydryl-compounds restarts the proton pump and reactivates sperm motility. Cobaltous ions block the membrane sulfhydryl groups and it is proposed that the sulfhydryl groups may be involved in regulating proton secretion and sperm motility.