title: Inhibition of the acrosome reaction of sea urchin spermatozoa by a calmodulin antagonist, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7).
abstract: A calmodulin antagonist, W-7 (N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide), inhibited induction of the acrosome reaction of sea urchin spermatozoa by egg jelly at 20-50 microM, but W-5 did not. The latter, a chlorine-deficient derivative of W-7, has a lower affinity for calmodulin than does W-7. These results suggest that a Ca2+-calmodulin-dependent process plays an important role in the triggering process of the acrosome reaction of sea urchin spermatozoa.
mesh_terms: D000177:Acrosome / Q000187:drug effects*; D000818:Animals; D002118:Calcium / Q000037:antagonists & inhibitors; D002135:Calcium-Binding Proteins / Q000037:antagonists & inhibitors*; D002147:Calmodulin / Q000037:antagonists & inhibitors*; D008297:Male; D012617:Sea Urchins; D013094:Spermatozoa / Q000187:drug effects*; D013449:Sulfonamides / Q000494:pharmacology*
chemical_list: D002135:Calcium-Binding Proteins; D002147:Calmodulin; D013449:Sulfonamides; C017967:W 7; D002118:Calcium