Investigation of structural changes in human serum albumin after binding with elaidic acid

Abstract

Elaidic acid (EA) is an unsaturated trans-fatty acid and one of the most important fatty acids obtained from solidifying vegetable oils. The increase in the consumption of EA is associated with rise and decline of LDL-cholesterol and HDL-cholesterol levels, respectively. It activates pro-inflammatory markers in the body and increases heart stroke and cardiovascular diseases. In this study, to understand the impact of EA in humans, we investigated the molecular interaction between EA and human serum albumin (HSA) and its binding affinity using spectroscopic, molecular dynamics (MD), and molecular docking techniques. According to fluorescence quenching experiments, EA could quench the inherent fluorescence of HSA via a static quenching mechanism. The thermodynamic characteristics of EA binding on HSA demonstrated hydrogen bonds and Van der Waals forces within the interaction, which matched molecular docking results. Further, the negative amount of ΔG° indicated the spontaneous binding of HSA to EA. Based on Förster's resonance energy transfer, the spatial distance between EA and HSA was 3.493 nm. The far-UV circular dichroism spectrum showed the decrease in the contents of the β-sheet and α-helix in the HSA structure. According to the RMSF data, the HSA structure's flexibility was diminished. The molecular dynamic simulation and spectroscopic studies also indicated that the binding interactions altered the milieu of the Trp chromophore and HSA structures. All experimental data could be matched with molecular dynamics simulation.