Chymotrypsin-like enzymes are involved in sperm penetration through the vitelline coat of Ciona intestinalis egg.
In Ciona intestinalis, sperm penetration through the egg vitelline coat is an essential event of fertilization. We investigated whether trypsin- and chymotrypsin-like enzymes are involved in this event. Inhibitors and peptide substrates for chymotrypsin-like enzymes blocked the overall process of fertilization in a concentration-dependent manner. The inhibitory activity was specifically exerted on the step of sperm penetration. Chymotrypsin-like protease activity was identified in spermatozoa with the fluorogenic synthetic substrate Suc-Ala-Ala-Phe-AMC, which was the most effective substrate in blocking sperm penetration. These data indicate that a chymotrypsin-like protease activity is a sperm lysin of Ciona intestinalis.
Pinto
M R
MR
Institute of Protein Biochemistry and Enzymology, CNR, Napoli, Italy.
Hoshi
M
M
Marino
R
R
Amoroso
A
A
De Santis
R
R
D000595:Amino Acid Sequence; D000818:Animals; D053818:Chymases; D002938:Ciona intestinalis / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro / Q000187:drug effects; D008297:Male; D008969:Molecular Sequence Data; D009088:Mucoproteins / Q000494:pharmacology*; D012697:Serine Endopeptidases / Q000494:pharmacology*; D013084:Sperm-Ovum Interactions / Q000187:drug effects*; D013094:Spermatozoa / Q000201:enzymology*; D013379:Substrate Specificity; D014817:Vitelline Membrane / Q000187:drug effects*
D009088:Mucoproteins; C010393:lysin, gastropoda; D012697:Serine Endopeptidases; D053818:Chymases