Kvassman J, Pettersson G, Ryde-Pettersson U
Avdelningen för Biokemi, Kemicentrum, Lunds Universitet, Sweden.
Eur J Biochem. 1988 Mar 1;172(2):427-31. doi: 10.1111/j.1432-1033.1988.tb13905.x.
The catalytic interaction of glyceraldehyde-3-phosphate dehydrogenase with glyceraldehyde 3-phosphate has been examined by transient-state kinetic methods. The results confirm previous reports that the apparent Km for oxidative phosphorylation of glyceraldehyde 3-phosphate decreases at least 50-fold when the substrate is generated in a coupled reaction system through the action of aldolase on fructose 1,6-bisphosphate, but lend no support to the proposal that glyceraldehyde 3-phosphate is directly transferred between the two enzymes without prior release to the reaction medium. A theoretical analysis is presented which shows that the kinetic behaviour of the coupled two-enzyme system is compatible in all respects tested with a free-diffusion mechanism for the transfer of glyceraldehyde 3-phosphate from the producing enzyme to the consuming one.
已通过瞬态动力学方法研究了甘油醛-3-磷酸脱氢酶与甘油醛3-磷酸之间的催化相互作用。结果证实了先前的报道，即当通过醛缩酶作用于果糖1,6-二磷酸在偶联反应系统中生成底物时，甘油醛3-磷酸氧化磷酸化的表观Km至少降低50倍，但不支持甘油醛3-磷酸在两种酶之间直接转移而无需事先释放到反应介质中的提议。本文进行了理论分析，结果表明，在所有测试方面，偶联双酶系统的动力学行为与甘油醛3-磷酸从产生酶向消耗酶转移的自由扩散机制均相符。
