Flossdorf J, Marutzky R, Kula M R
Nucleic Acids Res. 1977 Jul;4(7):2455-66. doi: 10.1093/nar/4.7.2455.
Aminoalcohol-AMP esters, structurally related to the assumed intermediates of the amino acid activation reaction, behave as competitive inhibitors both with respect to the amino acid and ATP, when tested in the ATP-(32P) PPi-exchange or the tRNA-charging reaction. However, closer investigation of the binding of norvalinyl adenylate to isoleucyl-tRNA synthetase from Escherichia coli MRE 600 by an equilibrium method shows that only the amino acid is a true competitor, while ATP cannot displace the ester from binding. Pyrophosphate enhances the stability of the ester-enzyme complex whereas tRNA is without detectable influence.
氨基醇-AMP酯在结构上与假定的氨基酸活化反应中间体相关,当在ATP-(32P)PPi交换或tRNA充电反应中进行测试时,它对氨基酸和ATP均表现为竞争性抑制剂。然而,通过平衡法对来自大肠杆菌MRE 600的异亮氨酰-tRNA合成酶与正缬氨酰腺苷酸的结合进行更深入研究表明,只有氨基酸是真正的竞争者,而ATP不能从结合中取代酯。焦磷酸增强了酯-酶复合物的稳定性,而tRNA则没有可检测到的影响。