Manchester K L
Department of Biochemistry, University of the Witwatersrand, Johannesburg, South Africa.
Biochem Int. 1991 Dec;25(5):929-39.
The kinetics of the heterologous exchange of GDP bound to EF-Tu by free GTP catalysed by EF-Ts have been analysed with a view to correlating results obtainable with different computational procedures. The affinity of EF-Ts for EF-Tu.GTP was found to be somewhat less than previously proposed by Romero et al. (Biochemistry 260, 6167:1985) though still greater than for EF-Tu.GDP. There is a close interrelationship between the constants for the binding of GTP to EF-Tu.EF-Ts and of EF-Ts to EF-Tu.GTP. The declining fractional rate of exchange observed by Romero et al. during displacement of GDP by GTP appears to be dependent on the ratio of the rate constants (k-1 + k-2)k4/k1k-2 as defined in the text, not on that of K4/K1 as they proposed.
为了关联不同计算程序可获得的结果，对由EF-Ts催化的游离GTP与结合在EF-Tu上的GDP进行异源交换的动力学进行了分析。发现EF-Ts对EF-Tu.GTP的亲和力略低于Romero等人（《生物化学》260, 6167:1985）之前提出的亲和力，不过仍大于对EF-Tu.GDP的亲和力。GTP与EF-Tu.EF-Ts结合的常数以及EF-Ts与EF-Tu.GTP结合的常数之间存在密切的相互关系。Romero等人在GTP取代GDP过程中观察到的交换分数速率下降似乎取决于文中定义的速率常数之比(k-1 + k-2)k4/k1k-2，而不是他们所提出的K4/K1之比。
