Experimental and in silico investigation on the interaction of indomethacin with bovine serum albumin: Effect of sodium dodecyl sulfate surfactant monomers on the binding

Abstract This paper describes the interaction of indomethacin with bovine serum albumin (BSA) using experimental and computational approaches. Inner filter effect (IFE) had significantly impacted the fluorescence results as uncorrected data shown the considerable involvement of tyrosine residues which became very low after correcting the data with the former, thus, only the tryptophan residues were found to be associated with fluorescence quenching. Analyses of the corrected data suggested that there was 1:1 strong binding between BSA and indomethacin that taken place via static quenching mechanism. The binding was exothermic in nature and energetically favorable with ordering of the system. The binding of indomethacin remained almost unchanged in presence of low amount of sodium dodecyl sulfate (SDS) surfactants monomers while it significantly diminished when the concentration of SDS monomers increased. Low concentrations of indomethacin didn’t affect the secondary structure of BSA, however, high concentrations led to the partial unfolding of the protein. Molecular docking along with molecular dynamics simulation results explained that this drug molecule occupied new binding site with strong binding affinity of −8.35 kcal/mol, which is oriented in the interface between domain 1 and domain 2. The interaction was facilitated by both hydrophobic forces as well as hydrogen bonding.