Molecular docking and toxicity analysis of ribosome-inactivating protein and natural chemical compounds as promising antiretroviral candidates against HIV-1

Background: HIV (human immunodeficiency virus) uses HIV-1 reverse transcriptase as the receptor to convert RNA into viral DNA. In addition, the CD4 receptor is also used by the virus to enter CD4+ T cells and subsequently replicate. Objective: To screen several proteins in Indonesian plants for the potential to bind to the CD4 receptor. Method: Molecular docking was carried out on Cluspro 2.0 specifically for protein to protein and MOE for protein to ligand. Results: The protein ligands were Cinnamomin III, Agglutinin, PAP, PAP-S, Momordin I, MAP30, Beta-luffin, Luffaculin I, Cucurmosin, DAP, Dianthin-30, Bouganin, Maize, Ricin, Abrin, Balsamin, and the bond energy values  (Joules/kg.mol) were -602.8, -973.5, -511.3, -439.1, -532.2, -661.9, -487.0, -472.8, -530.9, -413.6, 444.1, -504.5, -617.2, -855.6, -883.9, -558.6, respectively. The best binding energy with CD4 was selected to identify the compound's molecule. These compounds were abrusin, abrusogenin, eicosadienoic acid, heneicosane, precatorine, and trigonelline, and the bond energy values (Joules/kg.mol) were -19.2158, -16.7057, -15.5155, -13.9632, -15.6119, and -9.2620, respectively. The toxicity test of abrusin was carried out against 18 targets, and two targets showed toxic activities. Conclusion: The content of RIP and natural chemical compounds in Abrus precatorius seeds make them the best candidate for antiretroviral therapy against HIV-1.