Stoichiometric measurement of the acrosin content of a guinea-pig spermatozoon.
Guinea-pig spermatozoa were induced to undergo an acrosome reaction with the ionophore A23187. A time course for the activation of protease activity was established. Acid treatment of fully activated spermatozoa at pH 2.35 for 30 min exposed additional activity. This was attributed to the acid dissociation of a protein inhibitor from acrosin. The acrosin content of fully activated and acid-dissociated sperm extracts was measured using a sensitive active-site titrant for serine proteases. The number of acrosin molecules per spermatozoon, calculated on the basis of the sperm count, was approximately 2 x 10(6), of which half were available without dissociation of the inhibitor.
Green
D P
DP
Department of Pharmacology, University of Otago Medical School, Dunedin, New Zealand.
D000176:Acrosin / Q000032:analysis*; D000177:Acrosome / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D006168:Guinea Pigs; D008297:Male; D012697:Serine Endopeptidases / Q000032:analysis*; D013094:Spermatozoa / Q000201:enzymology* / Q000502:physiology*
D000001:Calcimycin; D012697:Serine Endopeptidases; D000176:Acrosin