Interaction Study of 2,6‐Bis[4‐(4‐amino‐2‐trifluoromethyl phenoxy)benzoyl] Pyridine with Human Immunoglobulin by Optical Spectroscopy and Molecular Modeling

Abstract

The interaction between human immunoglobulin (HIgG) and BAFP (2,6-bis[4-(4-amino-2-trifluoromethyl phenoxy)benzoyl] pyridine was studied by fluorescence quenching, Fourier transform infrared (FT-IR) spectra and molecule modeling. The synchronous fluorescence spectra indicated the information on qualitative changes of the protein secondary structure in the presence of BAFP in aqueous solution. The quantitative alterations of the protein secondary structure were estimated by the evidences from FT-IR spectra with increases of α helices by about 2.6%-10.2%, increases of β-sheet structure by about 13.6%-27.7%, and reductions of β-turn structure by about 23.8%-30.3%. Molecular docking suggests that BAFP can strongly bind to HIgG. There are four hydrogen bond interactions between the drug and the residues Trp 170, Val 105, Met 139 and Asn 52. It was also considered that BAFP bound to HIgG mainly by a hydrophobic interaction, which is in good agreement with the results from the experimental thermodynamic parameters (the enthalpy change ∆H and the entropy change ∆S were calculated to be -6.70 kJ•mol -1 and 71.93 J•mol -1 •K -1 , respectively, according to the Van't Hoff equation).

Binding studies of costunolide and dehydrocostuslactone with HSA by spectroscopy and atomic force microscopy

“…A reasonable explanation was that the insertion of CE and DE molecule caused an increase in hydrophilicity of the binding pocket of site II, and weakened the hydrophobic interactions. The calculated binding Gibbs free energies (DG 0 ) were À24.69 kJ mol À 1 (5.90 kcal mol À 1 ) for HSA-CE interaction and À 23.99 kJ mol À 1 (5.73 kcal mol À 1 ) for HSA-DE interaction, which were close to the experimental values [À 22.44 kJ mol À 1 (CE) and À 21.93 kJ mol À 1 (DE) at 298 K] to some degree [20,21].…”

“…Although there is a lot of information on antimicrobial potential of CE and DE, the interactions of CE and DE with HSA have not yet been investigated in detail [2,19]. In this work, the interactions of CE and DE with HSA were studied by fluorescence, Fourier transformed infrared (FTIR), and circular dichroism (CD) spectroscopy methods as in our previous studies [20,21]. In addition, Raman spectroscopy and atomic force microscopy (AFM) were also employed to analyze the drug-HSA interactions.…”

Study of interaction between syringin and human serum albumin by multi-spectroscopic method and atomic force microscopy

“…Combined with the thermodynamic analysis, we believed that the hydrophobic interaction is the driven forces for the interaction between syringin and HSA although there are hydrogen bonds and electrostatic interactions. The calculated binding Gibbs free energy (DG 0 ) is À22.40 kJ mol À1 , which is close to the experimental value (À25.26 kJ mol À1 , 295 K) to a certain degree [15,16].…”

“…Thus, it has been an interesting research filed in life sciences, chemistry and clinical medicine. In this paper, the interaction between syringin with HSA has been thoroughly studied for first time by multi-spectroscopic method as our previous studies [15,16]. FTIR and circular dichroism (CD) spectra were employed to probe conformational changes induced by the drug.…”