Evaluation of the interaction between antiviral drug and DNA/BSA via comprehensive multispectral methods and molecular docking studies

Tenofovir disoproxil is a nucleotide analog reverse-transcriptase inhibitor, which is a crucial enzyme in retroviruses such as human immunodeficiency virus (HIV). Tenofovir is used for the treatment of chronic hepatitis B and to prevent and treat HIV/AIDS. In this study, the interactions between BSA and DNA with drug were evaluated by using UV–vis spectrophotometry, spectrofluorometric and molecular docking experiments. UV–vis experiments showed hyperchromic effect, which means drug, and BSA/DNA interacted and lead to change in protein and double helix conformation. Fluorescence quenching mechanism for the interaction between BSA and tenofovir was static, quenching (Kq) and binding (Kb) constants were 9.9 × 103 M−1 and 3.16 × 104 M−1, respectively. Synchronous fluorescence quenching studies indicated microenvironment of tryptophan residue of BSA changed with the interaction. Competitive fluorescence studies with methylene blue (MB) and acridine orange (AO) were verified that tenofovir and DNA interaction was groove binding. Molecular docking was performed to investigate the possible binding mode of tenofovir and interactions with BSA and DNA, which resulted in site I of BSA and minor groove of DNA being the binding site for tenofovir.