School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
Legislative Council Complex, Central, Hong Kong.
Biomol NMR Assign. 2021 Apr;15(1):143-151. doi: 10.1007/s12104-020-09997-w. Epub 2021 Jan 9.
E. coli nitroreductase NfsB (also called NfnB) has been studied extensively, largely due to its potential for cancer gene therapy. A homodimeric flavoprotein of 216 residues, it catalyses the reduction of nitroaromatics to cytotoxic hydroxylamines by NADH and NADPH and also the reduction of quinones to hydroxyquinones. Its role in vivo is not known but it is postulated to be involved in reducing oxidative stress. The crystal structures of the wild type protein and several homologues have been determined in the absence and presence of ligands, including nicotinate as a mimic of the headpiece of the nicotinamide cofactors. There is little effect on the overall structure of the protein on binding ligands, but, from the B factors, there appears to be a decrease in mobility of 2 helices near the active site. As a first step towards examining the dynamics of the protein in solution with and without ligand, we have assigned the backbone C, N, and H resonances of NfsB and examined the effect of the binding of nicotinate on the amide N, and H shifts.
大肠杆菌硝基还原酶 NfsB（也称为 NfnB）已被广泛研究，主要是因为其在癌症基因治疗方面的潜力。它是一种由 216 个残基组成的同二聚体黄素蛋白，通过 NADH 和 NADPH 催化硝基芳烃还原为细胞毒性羟胺，并催化醌还原为羟基醌。其在体内的作用尚不清楚，但据推测它参与了减轻氧化应激。野生型蛋白和几种同源物的晶体结构已在无配体和有配体的情况下确定，包括烟酸盐作为烟酰胺辅因子头部的模拟物。结合配体对蛋白质的整体结构几乎没有影响，但是，从 B 因子来看，靠近活性位点的 2 个螺旋的流动性似乎有所降低。作为研究配体存在和不存在时蛋白质在溶液中动力学的第一步，我们已经对 NfsB 的骨架 C、N 和 H 共振进行了归属，并研究了烟酸盐结合对酰胺 N 和 H 位移的影响。
