In vitro AND In silico ASSESSMENT OF HUMAN SERUM ALBUMIN INTERACTIONS WITH OMEGA 3-6-9 FATTY ACIDS

The interaction between human serum albumin (HSA) and omega 3-6-9 fatty acids (omega-3, omega-6, and omega-9), as unsaturated fatty acids, has been investigated using various methods including UV-vis spectrophotometry, circular dichroism (CD) spectroscopy, ELISA, lifetime and fluorescence anisotropy measurements, and the visual molecular dynamics (MD) simulation. The thermodynamic parameters of HSA thermal and chemical denaturation were assessed with and without omega 3-6-9 fatty acids. The T-m and Delta G((298K)())(0) of sole HSA were 327.7 K and 88 kJ/mol respectively. These figures for HSA treatment with 10 mu M omega-3, omega-6, and omega-9 were 326.2 K and 87 kJ/mol, 319.07 K and 87 kJ/mol, and 313.23 K and 86 kJ/mol, respectively. The same manner of reduction in Gibbs free energy, which is a protein stability criterion, was achieved in chemical denaturation by urea in presence of omega 3-6-9 fatty acids. The interaction of omega 3-6-9 fatty acids with HSA was confirmed after comparing it with L-thyroxin through ELISA assay. Although, evaluation of the regular secondary structure of HSA using CD showed a minor change after incubation with omega 3-6-9 fatty acids, its tertiary structure revealed an observable fluctuation. Thus, it seems that the interaction of omega 3-6-9 fatty acids with HSA leads to instability and partial structural changes. Furthermore, the molecular docking results indicated that the binding affinity of omega-3, omega-6, and omega-9 to subdomain ILA of HSA was higher than subdomain M. These results provide valuable insights into the binding mechanism of omega 3-6-9 fatty acids to HSA, which could play an important role in medicinal drug delivery.