Thioredoxins, small disulphide-containing redox proteins, play an important role in the regulation of cellular thiol redox balance through their disulfide reductase activity. In this study, we have identified, cloned, purified and characterized thioredoxin 1 (HvTrx1) from the Cnidarian Hydra vulgaris Ind-Pune. Bioinformatics analysis revealed that HvTrx1 contains an evolutionarily conserved catalytic active site Cys-Gly-Pro-Cys and shows a closer phylogenetic relationship with vertebrate Trx1. Optimum pH and temperature for enzyme activity of purified HvTrx1 was found to be pH 7.0 and 25°C, respectively. Enzyme activity decreased significantly at acidic or alkaline pH as well as at higher temperatures. HvTrx1 was found to be expressed ubiquitously in whole mount in situ hybridization. Treatment of Hydra with hydrogen peroxide (H2O2), a highly reactive oxidizing agent, led to a significant increase in gene expression and enzyme activity of Trx1. Further experiments using PX12, an inhibitor of Trx1, indicated that Trx1 plays an important role in regeneration in Hydra. Finally, by using growth assay in Escherichia coli and wound healing assay in human colon cancer cells, we demonstrate that HvTrx1 is functionally active in both prokaryotic and eukaryotic heterologous systems.

中文翻译：

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刺胞长蛇的硫氧还蛋白 1 的克隆和表征

硫氧还蛋白是一种含有二硫化物的小氧化还原蛋白，通过其二硫化物还原酶活性在调节细胞硫醇氧化还原平衡中发挥重要作用。在这项研究中，我们已经从 Cnidarian Hydra vulgaris Ind-Pune 中鉴定、克隆、纯化和表征了硫氧还蛋白 1 (HvTrx1)。生物信息学分析表明，HvTrx1 包含一个进化上保守的催化活性位点 Cys-Gly-Pro-Cys，并显示出与脊椎动物 Trx1 更密切的系统发育关系。发现纯化的 HvTrx1 酶活性的最佳 pH 值和温度分别为 pH 7.0 和 25°C。在酸性或碱性 pH 值以及较高温度下，酶活性显着降低。发现 HvTrx1 在整个原位杂交中普遍表达。用过氧化氢 (H2O2) 处理 Hydra，一种高反应性氧化剂，导致 Trx1 的基因表达和酶活性显着增加。使用 Trx1 抑制剂 PX12 的进一步实验表明，Trx1 在 Hydra 的再生中起重要作用。最后，通过在大肠杆菌中使用生长试验和在人结肠癌细胞中进行伤口愈合试验，我们证明 HvTrx1 在原核和真核异源系统中都具有功能活性。