In silico evaluation of DsiRNA-mediated targeting of arginase in Anopheles gambiae as a novel vector control strategy

Abstract

The rapid increase of resistance to insecticides among Anopheles mosquitoes, the primary vectors of malaria, highlights the necessity for new approaches in controlling vectors. RNA interference (RNAi) offers a targeted and environmentally safer alternative approach. Arginase in Anopheles gambiae, involved in nitrogen metabolism, presents a compelling target due to its potential role in modulating mosquito immune responses and influencing parasite development and vectorial competency. The study focused on designing and evaluating Dicer-substrate small interfering RNA (DsiRNA) molecules targeting arginase in An. gambiae to disrupt parasite development and reduce malaria transmission. DsiRNAs were designed using Integrated DNA Technologies and optimized based on GC content, secondary structure prediction, thermodynamic parameters, and off-target screening. The derived 21-mer guide strands were further evaluated through molecular docking to assess interactions with An. gambiae Ago2. To validate the docked complex for stability, a molecular dynamics (MD) simulation using 100 ns was performed, revealing stable RMSD trajectories, sustained hydrogen bonding, maintained structural compactness, and minimal residue fluctuation, indicating persistent Ago2-guide strand interactions under physiological conditions. Eight DsiRNAs demonstrated optimal biophysical and specificity profiles, among which DsiRNA6, followed by DsiRNA8, and DsiRNA1 exhibited favorable binding energy and dynamic stability. These findings highlight the structural feasibility and functional potential of selected DsiRNAs as candidates for arginase knockdown in An. gambiae and support RNAi-based strategies as promising alternatives for vector control.

Keywords: Arginase; DsiRNA design; Molecular docking; RNA interference, Anopheles gambiae.