Title
Synthesis, characterization and serum albumin binding studies of vitamin K3 derivatives
Author
Murugesan Suganthi, Kuppanagounder P. Elango
Year
2017
Journal
Journal of Photochemistry and Photobiology B: Biology
Abstract
Synthesis, characterization and bovine serum albumin (BSA) binding properties of three derivatives of vitamin K3 have been described. Results of UV–Vis and fluorescence spectra indicate complexation between BSA and the ligands with conformational changes in protein, which is strongly supported by synchronous and three dimensional fluorescence studies. Addition of the ligands quenches the fluorescence of BSA which is accompanied by reduction in quantum yield (Ф) from 0.1010 to 0.0775–0.0986 range. Thermodynamic investigations reveal that hydrophobic interaction is the major binding force in the spontaneous binding of these ligands with BSA. The binding constants obtained depend on the substituent present in the quinone ring, which correlates linearly with the Taft's field substituent constant (σF). The results show that compound with strong electron withdrawing nitro-group forms relatively stronger complex with BSA than amino and thioglycolate substituted ones. Circular dichroism studies show that the α-helical content of the protein, upon complexation with the ligands, decreases in the case of amino and nitro substituted vitamin K3 while increases in thioglycolate substituted compound. Molecular docking studies indicated that the vitamin K3 derivatives are surrounded by hydrophobic residues of the BSA molecule, which is in good agreement with the results of fluorescence spectral and thermodynamic studies.
Instrument
J-810
Keywords
Circular dichroism, Secondary structure, Ligand binding, Biochemistry