大熊猫子宫钙调素的分离纯化和性质的研究

以大熊猫子宫为材料分离纯化了钙调素(Calmodulin,CaM),经SDS-PAGE,PAGE和等电聚焦电泳鉴定,表现均一。分子量为18800道尔顿,等电点为3.6。该蛋白质分子的N-末端为封闭的。大熊猫子宫钙调素具有其它来源钙调素所特有的一些性质。对环核苷酸磷酸二酯酶有明显的激活作用,还发现对超氧化物歧化酶也有一定的激活作用。电泳行为受Ca~(2+)影响而出现特征性电泳改变,在含有Ca~(2+)的SDS凝胶电泳中,电泳速度比EGTA存在对略快,在PAGE中,有Ca~(2+)比无Ca~(2+)对电泳速度略慢。大熊猫子宫钙调素的氨基酸组成中,Phe/Tyr为8:2,可观察到钙调素特征性紫外吸收光谱。

Purification and Some Properties of Calmodulin in Giant Panda Uterus

Calmodulin(CaM) was separated and purified from giant panda uterus by phenyl-Sepharose CL-4B affinity chromatography and DEAE-cellulose ion exchange chromatography. The purified CaM was shown to be homogeneous by SDS-PAGE, PAGE and IEF with a molecular weight of 18.8 kD, pI of 3.6. It has a blocked Nterminus. The electrophoretic mobility of giant panda uterus CaM effected by Ca~(2+) is similarly as that of the bovine brain CaM. Cyclic nucieotide phosphodiesterase and bovine red cell dismutase can be activated by giant panda uterus CaM. Among the 148 amino acid residues, there are 23 Asp, 29 Glu and no Trp. The Phe/Tyr ratio is 8:2. The characteristic UV absorption peaks are seen at about 252,258,264,267 and 275nm. A comparison between the properties of CaM from bovine brain and giant panda uterus indicates that they are strikingly similar to each other.