Decreased binding of calmodulin to bull sperm proteins during heparin-induced capacitation

• Published in: Biology of reproduction Vol. 42; no. 3; pp. 483 - 489
• Main Authors: Leclerc, P. (Centre de Researches du CHUL Ste-Foy, Quebec, Canada), Sirard, M.A, Chafouleas, J.G, Lambert, R.D
• Format: Journal Article
• Language: English
• Published: Madison, WI Society for the Study of Reproduction 01.03.1990
• Subjects: Animals; Biological and medical sciences; BULLS; CALCIO; CALCIUM; Calmodulin - metabolism; Calmodulin-Binding Proteins - metabolism; Carrier Proteins - metabolism; Cattle; Dose-Response Relationship, Drug; ESPERMATOZOO; Fertilization - drug effects; Fundamental and applied biological sciences. Psychology; Heparin - pharmacology; Male; Mammalian male genital system; Morphology. Physiology; POLISACARIDOS; POLYHOLOSIDE; POLYSACCHARIDES; PROTEINAS; PROTEINE; PROTEINS; Seminal Plasma Proteins; Sperm Capacitation - drug effects; SPERMATOZOA; SPERMATOZOIDE; TAUREAU; TORO; Vertebrates: reproduction; Spermatozoa; Gel electrophoresis; Ox; Fecundation; Dose activity relation; Binding protein; Vertebrata; Spermatozoid capacitation; Reproduction; Mammalia; Cholecalcin; Artiodactyla; Heparin; Ungulata
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1095/biolreprod42.3.483

The 125I-calmodulin gel overlay procedure was used to evaluate the effect of a heparin treatment on the calmodulin-binding proteins of bull spermatozoa. At concentrations that increase the in vitro fertilization rate of in vitro-matured oocytes, heparin induced a decrease in the binding to calmodulin (CaM) in 3 sperm proteins of 28, 30, and 49 kDa. The binding of these proteins to CaM was higher when Ca2+ was absent from the overlay procedure, and this binding was negatively correlated to the fertilization rate. These results suggest that sperm capacitation is associated with a decrease in the binding of CaM to the 28, 30, and 49 kDa sperm CaM-binding proteins. Implications of such a decrease are discussed.