Zhang Houshuang, Wang Zhonghua, Huang Jingwei, Cao Jie, Zhou Yongzhi, Zhou Jinlin
Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China.
Front Vet Sci. 2020 Feb 18;7:76. doi: 10.3389/fvets.2020.00076. eCollection 2020.
Thioredoxin peroxidases (TPxs) are ubiquitous cysteine-based peroxidases that reduce peroxides as part of antioxidant defenses and redox signaling and are essential for protection against adverse environment agents like reactive oxygen species (ROS) and reactive nitrogen species (RNS). To better systematically understand TPxs, we identified a novel 2-Cys peroxiredoxin-Q (BmTPx-Q) of . The full-length BmTPx-Q gene is 653 bp that consists of an intact open reading frame of 594 bp that encodes a 197-amino acid protein. The predicted protein has a molecular weight of 22.3 kDa and an isoelectric point of 9.18. Moreover, BmTPx-Q showed low identity at the amino acid level to other peroxiredoxins (Prxs) among the currently known subfamilies. The recombinant BmTPx-Q protein (rBmTPx-Q) was expressed in and purified with beads. The native protein BmTPx-Q was detected using mouse anti-BmTPx-Q polyclonal serum with western blotting and indirect immunofluorescence assay (IFA). In addition, enzyme activity was observed using nicotinamide adenine dinucleotide phosphate (NADPH) as substrate and triggered the NADPH-dependent reduction of the Trx/TrxR system. It was also discovered that BmTPx-Q mainly exists as a monomer whether under its native or functional states. In addition, when incubated with Chloroquine diphosphate salt for 24 h , the expression of BmTPx-Q showed a marked downward trend with the increase of drug concentration. These results suggest that uses BmTPx-Q to reduce and detoxify hydrogen peroxides to survive and proliferate inside the host. Furthermore, BmTPx-Q showed the lowest identity with host enzymes and could be a potential drug target for the development of novel strategies to control infection.
硫氧还蛋白过氧化物酶（TPxs）是普遍存在的基于半胱氨酸的过氧化物酶，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，对于抵御活性氧（ROS）和活性氮（RNS）等有害环境因子至关重要。为了更好地系统了解TPxs，我们鉴定了一种新型的2-半胱氨酸过氧化物酶Q（BmTPx-Q）。BmTPx-Q基因全长653 bp，由一个594 bp的完整开放阅读框组成，该阅读框编码一个197个氨基酸的蛋白质。预测的蛋白质分子量为22.3 kDa，等电点为9.18。此外，BmTPx-Q在氨基酸水平上与目前已知亚家族中的其他过氧化物酶（Prxs）的同源性较低。重组BmTPx-Q蛋白（rBmTPx-Q）在大肠杆菌中表达并用珠子纯化。使用小鼠抗BmTPx-Q多克隆血清通过蛋白质印迹和间接免疫荧光分析（IFA）检测天然蛋白BmTPx-Q。此外，以烟酰胺腺嘌呤二核苷酸磷酸（NADPH）为底物观察到酶活性，并引发了Trx/TrxR系统的NADPH依赖性还原。还发现BmTPx-Q无论是在天然状态还是功能状态下主要都以单体形式存在。此外，当与二磷酸氯喹孵育24小时时，BmTPx-Q的表达随药物浓度的增加呈明显下降趋势。这些结果表明，[病原体名称]利用BmTPx-Q来还原和解毒过氧化氢，以便在宿主体内生存和增殖。此外，BmTPx-Q与宿主酶的同源性最低，可能是开发控制[病原体名称]感染新策略的潜在药物靶点。
