Kim J J, Chakraburtty K, Mehler A H
J Biol Chem. 1977 Apr 25;252(8):2698-701.
The rate of transfer of amino acid from enzyme-bound aminoacyl adenylate to tRNA has been compared with the rate of esterification of free amino acid. The approach of Lövgren et al. (Lövgren, T. N. E., Heinonen, J., and Loftfield, R. B. (1975) J. Biol. Chem. 250, 3854-3860) was used, with 14C in the aminoacyl adenylate and 3H in the free amino acid and with both the lysine and isoleucine systems of Escherichia coli. In both systems kinetic analyses show more rapid transfer from the preformed enzyme complex when interference by the back reaction with inorganic pyrophosphate was eliminated. Parallel experiments, in which the amount of enzyme complex was measured, confirmed that aminoacyl adenylate is an intermediate in both systems. No evidence was found for an alternative mechanism.
已将氨基酸从酶结合的氨酰腺苷酸转移至tRNA的速率与游离氨基酸的酯化速率进行了比较。采用了勒夫格伦等人（勒夫格伦，T.N.E.，海诺宁，J.，和洛夫菲尔德，R.B.（1975年）《生物化学杂志》250，3854 - 3860）的方法，氨酰腺苷酸中含有14C，游离氨基酸中含有3H，并且使用了大肠杆菌的赖氨酸和异亮氨酸系统。在这两个系统中，动力学分析表明，当消除了与无机焦磷酸的逆反应的干扰时，从预先形成的酶复合物的转移更为迅速。测量酶复合物量的平行实验证实，氨酰腺苷酸在这两个系统中都是中间体。未发现替代机制的证据。
