Purification and characterization of rat relaxin.
Purification and characterization of rat relaxin.
复制标题
大鼠松弛素的纯化和表征。
作者：
O. Sherwood
从妊娠第20天收集的大鼠卵巢中获得两种高度纯化的松弛素，命名为CM1和CM2。分离方法为水萃取、Sephadex G-50分离和离子交换色谱法。CM1和CM2的产量约为140微克/geq卵巢新鲜组织。用小鼠耻骨联合生物测定法测定CM1和CM2的生物效力时，没有发现它们之间的差异。理化分析表明，CM1和CM2相似，但不完全相同。经超离心测定，CM1和CM2的分子量约为6000。在pH 4.3下，丙烯酰胺圆盘凝胶电泳分析表明，CM1和CM2具有不同的电泳迁移率。电聚焦结果表明，CM1和CM2的等电点pH分别为7.6和9.4。CM1和CM2的氨基酸组成相似，但不完全相同。十二烷基硫酸钠聚丙烯酰胺凝胶平板凝胶电泳显示，减少的大鼠松弛素和减少的猪松弛素比未减少的松弛素迁移更远。这一观察结果支持了这样一种观点，即大鼠松弛素和猪松弛素一样，由两条由二硫键连接的链组成。
Two highly purified forms of relaxin, designated CM1 and CM2, were obtained from rat ovaries collected on day 20 of gestation. The isolation procedure consisted of aqueous extraction, followed by fractionation with Sephadex G-50 and ion exchange chromatography. The yields of CM1 and CM2 were approximately 140 microgram/geq ovarian fresh tissue. No difference in biological potency between CM1 and CM2 was found when they were bioassayed with mouse pubic symphysis bioassays. Physicochemical analyses indicated that CM1 and CM2 were similar but not identical. The molecular weights of CM1 and CM2 were approximately 6000, as determined by ultracentrifugation. Analytical acrylamide disc gel electrophoresis at pH 4.3 demonstrated that CM1 and CM2 had different electrophoretic mobilities. Electrofocusing indicated the isoelectric points of CM1 and CM2 were pH 7.6 and pH 9.4, respectively. The amino acid compositions of CM1 and CM2 were similar but not identical. Slab gel electrophoresis in polyacrylamide gel with sodium dodecyl sulfate showed that both reduced rat relaxin and reduced porcine relaxin migrated farther than their unreduced forms. This observation supports the view that rat relaxin, like porcine relaxin, consists of two chains linked by disulfide bonds.