Autor(es): Singh, Meghna; Srivastava, K. K.; Bhattacharya, Shailja M.

Resumo: DEAD box proteins are putative RNA unwinding proteins found in organisms ranging from mammals to bacteria. We have identified a novel immunodominant cDNA clone, BmL3-helicase, encoding DEAD box RNA helicase by immunoscreening of a larval stage cDNA library of Brugia malayi. The cDNA Sequence exhibited strong Sequence homology to Caenorhabditis elegans and C. briggsae RNA helicase, a prototypic member of the DEAD (Asp-Glu-Ala-Asp) box protein family. The clone also showed similarity with RNA helicase of Wolbachia, an endosymbiotic bacterium of filarial parasite. It was overexpressed as similar to 50 kDa His-tag fusion protein, and ATP hydrolysis assay of recombinant enzyme showed that either ATP or dATP was required for the unwinding activity, indicating BmL3-helicase as an ATP/dATP-dependent RNA helicase. The recombinant protein also demonstrated cross-seroreactivity with human bancroftian sera. The presence of BmL3-helicase in various life stages of B. malayi was confirmed by immunoblotting of parasite-life-cycle extracts with polyclonal sera against the BmL3-helicase, which showed high levels of expression in microfilaria, L-3,L- and adult (both male and female) stages. In the absence of an effective macrofilaricidal agent and validated anti-filarial drug targets, RNA helicases could be utilized as a rational drug target for developing agents against the human filarial parasite.

Palavras-Chave: Dead Box Protein; Antibody-Responses; Vaccine Candidates; Crystal-Structure; Rna; Identification; Expression; Antigens; Complex; Target

Imprenta: Parasitology Research, v. 104, n. 4, p. 753-761, 2009

Identificador do objeto digital: 10.1007/s00436-008-1251-6

Descritores: Aedes aegypti - Biochemistry

Data de publicação: 2009