Effect of calmodulin-like protein from buffalo (Bubalus bubalis) seminal plasma on Ca2+, Mg(2+)-ATPase of purified plasma membrane of buffalo spermatozoa.
Buffalo sperm heads and tails were cleaved by sonication and isolated in relatively pure proportions i.e. 95% and 98% respectively, by discontinuous sucrose density-gradient centrifugation. Purified plasma membranes from the isolated sperm heads and tails were obtained by hypotonic treatment and brief sonication followed by discontinuous sucrose density-gradient centrifugation. Ca2+, Mg(2+)-ATPase activity was evident in plasma membrane from sperm heads and tails, although activity was greater in the latter. A calmodulin-like protein isolated from buffalo seminal plasma increased the Ca2+, Mg(2+)-ATPase of plasma membrane from the sperm heads and tails by 128 and 136% respectively. Based upon the data obtained here and elsewhere (Sidhu & Guraya, 1989a) a model is proposed which explains regulation of Ca2+ in buffalo spermatozoa and implicates calmodulin-like protein and Ca2+, Mg(2+)-ATPase in sperm acrosome reaction.
Sidhu
K S
KS
Department of Zoology, Punjab Agricultural University, Ludhiana.
Guraya
S S
SS
D000818:Animals; D002020:Buffaloes; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D002147:Calmodulin / Q000302:isolation & purification / Q000494:pharmacology*; D002458:Cell Fractionation; D002462:Cell Membrane / Q000201:enzymology*; D008297:Male; D012661:Semen / Q000737:chemistry*; D013094:Spermatozoa / Q000201:enzymology / Q000648:ultrastructure*
D002147:Calmodulin; D017301:Ca(2+) Mg(2+)-ATPase