Jarrett Joseph T, Wan Jason T
Department of Biochemistry and Biophysics, University of Pennsylvania, 905B Stellar-Chance Laboratories, 422 Curie Boulevard, Philadelphia, PA 19104, USA.
FEBS Lett. 2002 Oct 9;529(2-3):237-42. doi: 10.1016/s0014-5793(02)03349-5.
Ferredoxin (flavodoxin):NADP+ oxidoreductase (FNR) is an essential enzyme that supplies electrons from NADPH to support flavodoxin-dependent enzyme radical generation and enzyme activation. FNR is a monomeric enzyme that contains a non-covalently bound FAD cofactor. We report that reduced FNR from Escherichia coli is subject to inactivation due to unfolding of the protein and dissociation of the FADH(2) cofactor at 37 degrees C. The inactivation rate is temperature-dependent in a manner that parallels the thermal unfolding of the protein and is slowed by binding of ferredoxin or flavodoxin. Understanding factors that minimize inactivation is critical for utilizing FNR as an accessory protein for S-adenosyl-L-methionine-dependent radical enzymes and manipulating FNR as an electron source for biotechnology applications.
铁氧化还原蛋白（黄素氧还蛋白）：NADP⁺氧化还原酶（FNR）是一种必需酶，它从NADPH提供电子，以支持黄素氧还蛋白依赖性酶自由基的产生和酶的激活。FNR是一种单体酶，含有一个非共价结合的FAD辅因子。我们报道，来自大肠杆菌的还原型FNR在37℃时会因蛋白质的解折叠和FADH₂辅因子的解离而失活。失活速率与温度有关，其方式与蛋白质的热解折叠相似，并且通过铁氧化还原蛋白或黄素氧还蛋白的结合而减缓。了解使失活最小化的因素对于将FNR用作依赖S-腺苷-L-甲硫氨酸的自由基酶的辅助蛋白以及将FNR作为生物技术应用的电子源进行操控至关重要。
