Sidhu K S
Department of Zoology, Punjab Agricultural University, Ludhiana, India.
Cell Mol Biol Res. 1995;41(6):569-73.
A procedure is described for the isolation, identification, and purification of plasma membrane from buffalo ejaculated spermatozoa. A typical yield of plasma membrane vesicles obtained by this procedure was 280 micrograms of membrane protein per (10)9 spermatozoa. Kinetics of calcium transport through purified plasma membrane vesicles were studied using 45Ca2+. The transport of Ca2+ through plasma membrane vesicles was electrogenic with maximum Ca2+ uptake (47 mumol) occurring at 30 min in the presence of 0.25 mM ATP. Km and V(max) values for Ca2+ transport were 0.25 mM and 182 mumol, respectively, whereas in the presence of variable concentrations of free Ca2+, the Km and V(max) values were 0.23 mumol and 82.3 mumol, respectively. Calmodulin-like protein (20 micrograms) significantly (p < 0.01) inhibited the Ca2+ accumulation in the plasma membrane vesicles. It is demonstrated that calmodulin-like protein regulates Ca2+ transport during sperm capacitation and acrosome reaction.
本文描述了一种从水牛射出的精子中分离、鉴定和纯化质膜的方法。通过该方法获得的质膜囊泡的典型产量为每（10）9个精子280微克膜蛋白。使用45Ca2+研究了钙通过纯化的质膜囊泡的转运动力学。Ca2+通过质膜囊泡的转运是生电的，在0.25 mM ATP存在下，30分钟时Ca2+摄取量最大（47 μmol）。Ca2+转运的Km和V（max）值分别为0.25 mM和182 μmol，而在游离Ca2+浓度可变的情况下，Km和V（max）值分别为0.23 μmol和82.3 μmol。钙调蛋白样蛋白（20微克）显著（p < 0.01）抑制质膜囊泡中Ca2+的积累。结果表明，钙调蛋白样蛋白在精子获能和顶体反应过程中调节Ca2+转运。
