Jebaseelan Jefrillah, Natesan Sankar, Balakrishnan Anand Setty
Department of Genetic Engineering, School of Biotechnology, Madurai Kamaraj University, Madurai, India.
Department of Epidemiology and Public Health, Central University of Tamil Nadu, Thiruvarur, India.
Acta Parasitol. 2025 Jul 22;70(4):166. doi: 10.1007/s11686-025-01104-0.
Lymphatic filariasis, caused by three major filarial species, is marked by immune evasion strategies involving antioxidant enzymes. The role of selenium-dependent glutathione peroxidase (SeGPx) in this process remains underexplored. This study aimed to identify and characterise SeGPx in Setaria digitata, a genomic analogue of Wuchereria bancrofti, and evaluate its potential as a diagnostic antigen.
segpx sequences were identified through bioinformatics tools, including BLAST and UniProt databases. Due to limited nematode entries, a validated SeGPx sequence from Lymnaea stagnalis was used as a proxy in PSI-BLAST to identify homologues. Enzymatic activity was confirmed through spectrophotometric assay and activity staining on SDS-PAGE to confirm its enzymatic activity and molecular mass confirmation.
The segpx gene was localised within the S. digitata genome data (Contig 127, nucleotides 56,000-58,000). The enzyme assay showed a time-dependent decline in absorbance at 340 nm due to NADPH oxidation, plateauing after 13 min. Enzyme activity was calculated as 0.139 U, with a specific activity of 0.198 U/mg protein. A clear band at ~ 20 kDa was visualised via activity staining, confirming SeGPx presence.
Combined sequence-based identification and enzymatic validation confirm the functional presence of SeGPx in S. digitata. These findings support its role in oxidative stress mitigation and potential as a diagnostic antigen. The precise gene localisation offers a foundation for recombinant cloning, providing a streamlined alternative to conventional purification approaches for diagnostic development in filariasis.
由三种主要丝虫引起的淋巴丝虫病的特征是存在涉及抗氧化酶的免疫逃避策略。硒依赖性谷胱甘肽过氧化物酶（SeGPx）在此过程中的作用仍未得到充分研究。本研究旨在鉴定和表征班氏吴策线虫的基因组类似物指状丝虫中的SeGPx，并评估其作为诊断抗原的潜力。
通过生物信息学工具，包括BLAST和UniProt数据库，鉴定segpx序列。由于线虫条目有限，在PSI-BLAST中使用来自椎实螺的经过验证的SeGPx序列作为替代物来鉴定同源物。通过分光光度法测定和SDS-PAGE上的活性染色来确认酶活性，以确认其酶活性和分子量。
segpx基因定位于指状丝虫基因组数据中（重叠群127，核苷酸56,000 - 58,000）。酶测定显示，由于NADPH氧化，在340nm处吸光度随时间下降，13分钟后趋于平稳。酶活性计算为0.139 U，比活性为0.198 U/mg蛋白质。通过活性染色在约20 kDa处可见一条清晰的条带，证实了SeGPx的存在。
基于序列的鉴定和酶学验证相结合，证实了指状丝虫中SeGPx的功能存在。这些发现支持了其在减轻氧化应激中的作用以及作为诊断抗原的潜力。精确的基因定位为重组克隆提供了基础，为丝虫病诊断开发的传统纯化方法提供了一种简化的替代方法。
