Zhang N Z, Liu J Y, Li W H, Li L, Qu Z G, Li T T, Cui J M, Yang Y, Jia W Z, Fu B Q
State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China.
State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Disease, Yangzhou 225009, PR China.
Vet Parasitol. 2016 Nov 15;231:53-58. doi: 10.1016/j.vetpar.2016.05.027. Epub 2016 May 24.
The intracellular parasitic nematode, Trichinella spiralis, can initiate a high level of oxidative stress, especially during rapid growth and generative propagation phases. Thioredoxin peroxidases (TPXs) protect helminths against oxidative stress, but none has been identified in T. spiralis. Here, 3 members of the TPX family were cloned from T. spiralis muscle larvae (ML). The lengths of TsTPX ORFs were 747bp, 588bp and 594bp, respectively, and the deduced proteins predicted to contain AhpC-TSA and 1-cys Prx_C domains. Interestingly, qRT-PCR data showed that TsTPX genes were expressed in all three developmental stages of T. spiralis. The TsTPX2 and TsTPX3 genes were up-regulated in day 3 adults (Ad3) compared with newborn larvae (NBL) and ML (P<0.05); expression levels of the TsTPX1 gene in ML were higher compared with Ad3 and NBL amounts (P<0.05). After prokaryotic expression, the reactivity of rTsTPX proteins was assessed by Western-blotting: only rTsTPX1 was specifically recognized by T. spiralis infection sera from pigs. Enzyme catalytic experiments showed that rTsTPX proteins could deoxidize HO in the presence of DTT, with the catalytic ability increasing with protein concentration and time.
细胞内寄生线虫旋毛虫可引发高水平的氧化应激，尤其是在快速生长和生殖繁殖阶段。硫氧还蛋白过氧化物酶（TPXs）可保护蠕虫免受氧化应激，但在旋毛虫中尚未发现此类蛋白。在此，从旋毛虫肌幼虫（ML）中克隆出了TPX家族的3个成员。旋毛虫硫氧还蛋白过氧化物酶（TsTPX）的开放阅读框（ORF）长度分别为747bp、588bp和594bp，推导的蛋白质预计含有AhpC-TSA和1-cys Prx_C结构域。有趣的是，定量逆转录聚合酶链反应（qRT-PCR）数据显示，TsTPX基因在旋毛虫的所有三个发育阶段均有表达。与新生幼虫（NBL）和ML相比，TsTPX2和TsTPX3基因在成虫第3天（Ad3）上调（P<0.05）；与Ad3和NBL相比，TsTPX1基因在ML中的表达水平更高（P<0.05）。原核表达后，通过蛋白质免疫印迹法评估重组TsTPX蛋白（rTsTPX）的反应性：只有rTsTPX1能被猪的旋毛虫感染血清特异性识别。酶催化实验表明，rTsTPX蛋白在二硫苏糖醇（DTT）存在的情况下可使过氧化氢（HO）脱氧，催化能力随蛋白质浓度和时间增加。
