Aluminum-adenine nucleotides as alternate substrates for creatine kinase.
Aluminum-adenine nucleotides as alternate substrates for creatine kinase.
复制标题
铝腺嘌呤核苷酸作为肌酸激酶的替代底物。
DOI：
10.1016/0003-9861(89)90346-9
复制
发表时间：
1989
影响因子：
3.9
通讯作者：
Viola,RE
中科院分区：
文献类型：
--
作者：
Furumo,NC;Viola,RE
Aluminum-ATP has previously been shown to be a potent but selective inhibitor of certain kinases (N. C. Furumo and R. E. Viola (1989)Inorg. Chem.28, 820–823). Because of the selective binding affinity that has been demonstrated, aluminum-ATP was examined as a potential alternate substrate for enzyme-catalyzed phosphoryl-transfer reactions. Of the kinases that have been examined only creatine kinase, which was weakly inhibited by Al-ATP, was found to utilize this metal-nucleotide complex as a substrate. The maximum velocity for this reaction is 0.6% of that observed with Mg-ATP, and a Michaelis constant of 90 μmwas measured, which is comparable to that with Mg-ATP. The equilibrium constant for the reaction, measured by phosphorus-31 NMR spectroscopy, is 0.18. This value is indistinguishable from the value determined for the reaction with Mg-ATP as the phosphoryl donor. The rate of interconversion between reactants and products at stoichiometric levels of creatine kinase was found to be quite rapid in the presence of Al3+, indicating that the rate-limiting step in catalytic turnover for this substrate must be a slow rate of substrate binding and/or product release.
