Jacquot J P, de Lamotte F, Fontecave M, Schürmann P, Decottignies P, Miginiac-Maslow M, Wollman E
Physiologie Végétale Moléculaire UA CNRS 1128, Orsay, France.
Biochem Biophys Res Commun. 1990 Dec 31;173(3):1375-81. doi: 10.1016/s0006-291x(05)80940-4.
The reactivity of human thioredoxin (HTR) was tested in several reactions. HTR was as efficient as E. coli or plant and algal thioredoxins when assayed with E. coli ribonucleotide reductase or for the reduction of insulin. On the other hand, HTR was poorly reduced by NADPH and the E. coli flavoenzyme NADPH thioredoxin reductase as monitored in the DTNB reduction test. When reduced with dithiothreitol (DTT), HTR was much less efficient than thioredoxin m and thioredoxin f, the respective specific thioredoxins for the chloroplast enzymes NADP-malate dehydrogenase (NADP-MDH) and fructose 1,6 bisphosphatase (FBPase). Finally, HTR could be used in the photoactivation of NADP-MDH although less efficiently than thioredoxin m, proving nevertheless that it can be reduced by the iron sulfur enzyme ferredoxin thioredoxin reductase in the presence of photoreduced ferredoxin. Based on sequence comparisons, it was expected that HTR would display a reactivity similar to chloroplast thioredoxin f rather than to thioredoxin m. However the observed behavior of FTR did not exactly fit this prediction. The results are discussed in relation to the structural data available for the proteins.
在多个反应中测试了人硫氧还蛋白（HTR）的反应活性。当用大肠杆菌核糖核苷酸还原酶进行测定或用于胰岛素还原时，HTR与大肠杆菌、植物和藻类硫氧还蛋白一样高效。另一方面，在DTNB还原试验中监测到，NADPH和大肠杆菌黄素酶NADPH硫氧还蛋白还原酶对HTR的还原效果较差。用二硫苏糖醇（DTT）还原时，HTR的效率远低于硫氧还蛋白m和硫氧还蛋白f，它们分别是叶绿体酶NADP-苹果酸脱氢酶（NADP-MDH）和果糖1,6-二磷酸酶（FBPase）的特异性硫氧还蛋白。最后，HTR可用于NADP-MDH的光激活，尽管效率低于硫氧还蛋白m，但这证明在光还原铁氧还蛋白存在的情况下，它可被铁硫酶铁氧还蛋白硫氧还蛋白还原酶还原。基于序列比较，预计HTR的反应活性与叶绿体硫氧还蛋白f相似，而不是与硫氧还蛋白m相似。然而，观察到的HTR行为并不完全符合这一预测。结合蛋白质的现有结构数据对结果进行了讨论。
