【摘要】 用改进的Ｋｕｂｙ等人方法从大熊猫骨骼肌中纯化了肌酸激酶，并对此酶的某些性质进行了研究。纯化倍数为 ３５．７；收率１７．３％；比活力为 ５５．３Ｕ／ｍｇ；等电点为 ６．６０。聚丙烯酰胺凝胶电泳鉴定为一条带。ＳＤＳ聚丙烯酰胺凝胶电泳测得其亚基分子量为４２ ０００，总分子量为 ８４ ０００，该酶是由两个相同亚基组成的二聚体。酶对肌酸的Ｋｍ 为 ５．２６ｍｍｏｌ／Ｌ；对ＡＴＰ的 Ｋｍ为 ０．７４ｍｍｏｌ／Ｌ，酶的最适温度是 ３０～３６℃；酶的最适ｐＨ大于８．０。更多还原

【Abstract】 Creatine kinase (ATP:creatine N-phosphoLransferase, EC 2.7.3.2) was isolated and purified from skeletal muscle of giant panda by method B of Kuby followed by DEAE-cellulose chromatography. The overall yield was 17.3% with purification ratio of 35.7 fold. The purified component was proved to be homogeneous in polyacrylamide gel electrophoresis. The specific activity was 55.5 U/mg protein. This enzyme is dimeric, consisting of two identical subunits each with a molecular weight of 42 000 as determined by SDS-PAGE. The isoelectric point of purified enzyme was 6.60. H. (ATP) and X. (Cr)were 0.74mmol/L and 5.26mmol/L respectively. The enzyme exhibited optimal activity at pH 8.0-9.5 and 30-36℃. The amino acid composition of the enzyme was also determined.更多还原