Buchko Garry W, Perkins Arden, Parsonage Derek, Poole Leslie B, Karplus P Andrew
Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR, 97331, USA.
Biomol NMR Assign. 2016 Apr;10(1):57-61. doi: 10.1007/s12104-015-9637-8. Epub 2015 Sep 15.
Peroxiredoxins (Prx) are ubiquitous enzymes that reduce peroxides as part of antioxidant defenses and redox signaling. While Prx catalytic activity and sensitivity to hyperoxidative inactivation depend on their dynamic properties, there are few examples where their dynamics has been characterized by NMR spectroscopy. Here, we provide a foundation for studies of the solution properties of peroxiredoxin Q from the plant pathogen Xanthomonas campestris (XcPrxQ) by assigning the observable (1)H(N), (15)N, (13)C(α), (13)C(β), and (13)C' chemical shifts for both the reduced (dithiol) and oxidized (disulfide) states. In the reduced state, most of the backbone amide resonances (149/152, 98 %) can be assigned in the XcPrxQ (1)H-(15)N HSQC spectrum. In contrast, a remarkable 51 % (77) of these amide resonances are not visible in the (1)H-(15)N HSQC spectrum of the disulfide state of the enzyme, indicating a substantial change in backbone dynamics associated with the formation of an intramolecular C48-C84 disulfide bond.
过氧化物酶（Prx）是一种普遍存在的酶，作为抗氧化防御和氧化还原信号传导的一部分，可还原过氧化物。虽然Prx的催化活性和对过度氧化失活的敏感性取决于其动态特性，但很少有例子通过核磁共振光谱对其动态特性进行表征。在这里，我们通过确定植物病原体野油菜黄单胞菌（XcPrxQ）中过氧化物酶Q在还原态（二硫醇）和氧化态（二硫键）下可观测的（1）H（N）、（15）N、（13）C（α）、（13）C（β）和（13）C'化学位移，为研究其溶液性质奠定了基础。在还原态下，XcPrxQ的（1）H-（15）N HSQC谱中大部分主链酰胺共振峰（149/152，98%）可以被归属。相比之下，在该酶二硫键状态的（1）H-（15）N HSQC谱中，这些酰胺共振峰中有高达51%（77个）不可见，这表明与分子内C48-C84二硫键形成相关联的主链动力学发生了显著变化。
