Identification of the NADH-oxidase gene in Trichomonas vaginalis
Identification of the NADH-oxidase gene in Trichomonas vaginalis
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DOI：
10.1007/s00436-019-06572-8
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发表时间：
2020-02-01
影响因子：
2
通讯作者：
Leitsch, David
中科院分区：
文献类型：
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作者：
Lamien-Meda, Aline;Leitsch, David
微需氧人体寄生虫阴道毛滴虫会引起泌尿生殖道感染，是全世界最常见的性传播病原体之一。由于其无氧代谢，它必须快速去除细胞内的氧气，以避免必需的代谢酶失活，例如氧敏感的丙酮酸：铁氧还蛋白氧化还原酶（PFOR）。已在阴道毛滴虫黄素还原酶（以前称为 NADPH 氧化酶，通过黄素单核苷酸 (FMN) 间接将氧还原为过氧化氢）和 NADH 氧化酶（将氧还原为水）中鉴定出负责去除（即还原）分子氧的两种主要酶活性。黄素还原酶已在基因水平和酶学水平上得到鉴定和表征，但 NADH 氧化酶迄今为止仅使用从阴道毛滴虫细胞提取物中分离的酶进行酶学表征。在这项研究中，我们从 NADH 氧化酶活性染色呈阳性的凝胶条带中分离出酶后，通过质谱法鉴定了 NADH 氧化酶。在已知完全缺乏 NADH 氧化酶活性的菌株 C1 (ATCC 30001) 中，NADH 氧化酶基因在开放阅读框的位置 1540 处有缺失，导致移码，从而导致所编码的多肽过早终止。
The microaerophilic human parasite Trichomonas vaginalis causes infections in the urogenital tract and is one of the most often sexually transmitted pathogens worldwide. Due to its anaerobic metabolism, it has to quickly remove intracellular oxygen in order to avoid deactivation of essential metabolic enzymes such as oxygen-sensitive pyruvate:ferredoxin oxidoreductase (PFOR). Two major enzyme activities which are responsible for the removal, i.e. reduction, of molecular oxygen have been identified in T. vaginalis flavin reductase, formerly designated NADPH oxidase, which indirectly reduces oxygen to hydrogen peroxide via flavin mononucleotide (FMN), and NADH oxidase which reduces oxygen to water. Flavin reductase has been identified and characterized at the gene level as well as enzymatically, but NADH oxidase has so far only been characterized enzymatically with enzyme isolated from T. vaginalis cell extracts. In this study, we identified NADH oxidase by mass spectrometry after isolation of the enzyme from gel bands positively staining for NADH oxidase activity. In strain C1 (ATCC 30001) which is known to lack NADH oxidase activity completely, the NADH oxidase gene has a deletion at position 1540 of the open reading frame leading to a frame shift and, as a consequence, to premature termination of the encoded polypeptide.