Sequence Localization of SeGPx in S. digitata Genome Contigs and Determination of its Presence in the Whole Worm Extract.

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.