萌发百合花粉中一种低分子量鸟苷三磷酸酶的研究

Purification and Characterization of a 38 kD GTPase from Pollen Tubes of Lily

研究表明，鸟苷三磷酸酶（ＧＴＰ酶）超家族是细胞中一类重要的酶类．其功能之一是水解ＧＴＰ或ＡＴＰ，提供细胞生存和运动所需要的能量，如已发现的具ＧＴＰ酶活性的微管相关马达蛋白、动蛋白和力蛋白等，在微管系统相关运动中提供所需的动力，其分子量一般较大，在１０...

The purification and characterization of a GTPase from pollen tubes of Lilium davidii were studied.The GTPase was purified to homogeneity,through acetone powder preparation,Sephadex G200 gel filtration,DEAE Sepharose Fast Flow ion exchange,Sephacryl S 100.The GTPase was purified to 21 2 fold,resulted in 1 95 milligrams enzyme protein per 20 grams of pollen acetone powder.Molecular weight of the GTPase detected by SDS PAGE was 38 kD.The K m of the GTPase to GTP was 1.18×10 -3 mol/L and its V max was 333.3 nmol·min -1 ·mg -1 ,whereas ATP,CTP,UTP were 34.5,23.0,3.8,respectively.Inhibited properties of different inhibitor on the GTPase showed that hydrolysis of the GTPase was markedly inhibited by NaVO 3,NEM,oligomycin,KNO 3 and ouabain.Western blotting results showed that,the GTPase was not similar to GTP or ATP dependent motor proteins,such as dynein and kinesin and myosin.