Mg^(2+)和Ca^(2+)对兔心肌单离腺苷酸环化酶的调节机制  

Effect of Magnesium and Calcium on Adenylate Cyclase Separated from Rabbit Heart

作　　者：张岐山[1] 魏金荣[1] 张玉魁[1] 孟冬娅[1] 刘金兰[2] 姜敏[2] 

机构地区：[1]中国医科大学基础医学部生物化学教研室 [2]中国医科大学附属第一医院内科

出　　处：《中国医科大学学报》1993年第6期418-421,共4页Journal of China Medical University

基　　金：国家自然科学基金

摘　　要：用兔心肌可溶性肌纤维膜和层析分离的腺苷酸环化酶(AC)组分制备人工蛋白脂质体,并观察Mg^(2+)和Ca^(2+)对上述两种蛋白脂质体中AC的影响。结果表明,Mg^(2+)激活AC在可溶性肌纤维膜的蛋白脂质体中有两种不同的亲和常数,分别为0.14mmol/L和1.1mmol/L。其中高亲和常数在AC组分的调节部位,低亲和常数是Mg^(2+)和GTP结合蛋白质的结合部位。Ca^(2+)抑制AC的活性,它的抑制常数为30μmol/L。Mg^(2+)和Ca^(2+)对AC的作用是竞争性的。This paper studied the effect of Mg^(2+)and Ca^(2+)on adenylate cyclase of proteoliposomes, which were prepared from soluble sareolemma of rabbit heart and separated adenylate cyclase by chromatography respectivly. The results demonstrated that, the activity of adenylate cyclase was activated by Mg^(2+) and there were two different affinity constants in soluble sarcolemma of rabbit heart. The higher affinity constasnt equaled the affinity constant of separated adenylate cyclase. Ca^(2+) inhibited the activity of adenylate cyclase of rabbit heart and competed with the effect of Mg^(2+).

关 键 词：镁离子 钙离子 心脏 腺苷酸环化酶 

分 类 号：R362[医药卫生—病理学]