Investigating binding dynamics of trans resveratrol to HSA for an efficient displacement of aflatoxin B1 using spectroscopy and molecular simulation
M. A. Qureshi, Saleem Javed
Abstract
Abstract Resveratrol is a polyphenol belonging to the class stilbenes. The active and stable form of resveratrol is trans -resveratrol. This polyphenol is bestowed with numerous biological properties. Aflatoxin B 1 is a hepato-carcinogen and mutagen that is produced by Aspergillus species. In this study, the interaction of trans -resveratrol with HSA followed by competitive dislodging of AFB 1 from HSA by trans- resveratrol has been investigated using spectroscopic studies. The UV-absorption studies revealed ground state complex formation between HSA and trans -resveratrol. Trans -resveratrol binds strongly to HSA with the binding constant of ~ 10 7 M −1 to a single binding site (n = 1.58), at 298.15 K. The Stern–Volmer quenching constant was calculated as 7.83 × 10 4 M −1 at 298.15 K, suggesting strong fluorescence quenching ability of trans -resveratrol. Site markers displacement assay projected subdomain IIA as the binding site of trans -resveratrol to HSA. The molecular docking approach envisages the amino acid residues involved in the formation of the binding pocket. As confirmed from the site marker displacement assays, both trans -resveratrol and AFB 1 binds to HSA in the same binding site, subdomain IIA. The study explores the ability of trans -resveratrol to displace AFB 1 from the HSA-AFB 1 complex, thereby affecting the toxicokinetic behavior of AFB 1 associated with AFB 1 exposure.