微量热法研究Na^+,K^+-ATP_(ase)酶促反应  

Microcalorimetric Studies on Na^+,K^+-ATP_(ase)

作　　者：李霞[1] 王志勇[1] 谢修银[1] 张文婷[1] 汪存信[1] 

机构地区：[1]武汉大学化学与分子科学学院,湖北武汉430072

出　　处：《武汉大学学报（理学版）》2002年第4期397-400,共4页Journal of Wuhan University:Natural Science Edition

基　　金：国家自然科学基金资助项目 (3 0 0 70 2 0 0 )

摘　　要：首次用微量热方法研究了Na+ ,K+ ATPase催化ATP水解的酶促反应 在 310 .15K ,pH =7.4的 10 0mmol·L-1Tris HCl,10 0mmol·L-1NaCl,10mmol·L-1KCl,3mmol·L-1MgCl2 缓冲溶液环境下 ,用对比进度法得出了Na+ ,K+ ATPase酶促反应的米氏常数Km值和最大反应速率Vm值 所得常数值与文献给出的相符 并用比色法得出了一致的Km和Vm值For the first time, the hydrolysis reaction of ATP catalyzed by Na + ,K + \|ATP ase was studied with microcalorimetry. The Micheal Constant( K m ) and Maximal Velocity( V m ) of Na + , K + \|ATP ase under certain experimental conditions were determined by reduced extent method. The constants obtained above were in good coincidence with literature figure. Identical values of K m and V m were obtained by colorimetric determination of inorganic phosphate. The effect of excessive dilution on enzyme-catalyzed reaction was also investigated.

关 键 词：微量热 NA^+ K^+-ATPase 酶促反应 比色法 

分 类 号：O642.3[理学—物理化学]