Background:

Speract, a sea urchin egg peptide that regulates sperm motility, also stimulates sperm mitochondrial metabolism.

Speract is a decapeptide from the outer jelly layer of theStrongylocentrotus purpuratus egg that upon binding to its receptor in the sperm, stimulates sperm motility, respiration and ion fluxes, among other physiological events. Speract increases NADH levels and depolarizes the sea urchin sperm mitochondrion[1].

[1]. García-Rincón J, et al. Speract, a sea urchin egg peptide that regulates sperm motility, also stimulates sperm mitochondrial metabolism. Biochim Biophys Acta. 2016 Apr;1857(4):415-26.