Infrared spectroscopy of proteins.

Spectroscopic studies on the interaction of cinnamic acid and its hydroxyl derivatives with human serum albumin

Interactions of human serum albumin with chlorogenic acid and ferulic acid.

Milk β-lactoglobulin complexes with tea polyphenols.

We report the complexation of bovine serum albumin (BSA) with resveratrol, genistein, and curcumin, at physiological conditions, using constant protein concentration and various polyphenol contents. FTIR, CD, and fluorescence spectroscopic methods were used to analyze the ligand binding mode, the binding constant, and the effects of complexation on BSA stability and conformation. Structural analysis showed that polyphenols bind BSA via hydrophilic and hydrophobic interactions with the number of bound polyphenol (n) being 1.30 for resveratrol-BSA, 1.30 for genistein-BSA, and 1.0 for curcumin-BSA. The polyphenol-BSA binding constants were K(Res-BSA) = 2.52(+/-0.5) x 10(4) M(-1), K(Gen-BSA) = 1.26(+/-0.3) x 10(4) M(-1), and K(Cur-BSA) = 3.33(+/-0.8) x 10(4) M(-1). Polyphenol binding altered BSA conformation with a major reduction of alpha-helix and an increase in beta-sheet and turn structures, indicating a partial protein unfolding.

Resveratrol, genistein, and curcumin bind bovine serum albumin.

Studies on the hydrogen bonding of aniline's derivatives by FT-IR.

Studies on Amide III Infrared Bands for the Secondary Structure Determination of Proteins

The mechanism of the interaction between Chrysin (CHR) and human serum albumin (HSA) was investigated using various spectroscopic techniques. It was found that CHR can induce HSA fluorescence emission quenching by static process. Additionally, HSA caused a significant red shift in the ultraviolet absorption of CHR. This indicated that binding with a protein can result in dissociation of the phenolic hydroxyl in CHR. HSA can also cause CHR fluorescence emission. The binding constants of CHR and HAS were calculated based on the fluorescence quenching and emission modes. The results obtained using these two methods were consistent. The binding constant (KA) values at pH 7.4 were (9.97±0.24)×10 4 1 , respectively; and the ratio of combination was 1:1. The binding constants decreased gradually with decreasing the pH value. This is related to conformational changes in the protein. The protein is partly denatured at pH 3.5, with the site II in the HSA opening chain. It was found that CHR was located at site I, which is in subdomain IIA of HAS. Based on molecular modeling, the mechanism of the interaction between CHR and HAS was investigated.

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Liu Yuan

Papers

Spectroscopic studies on the interaction of cinnamic acid and its hydroxyl derivatives with human serum albumin

Studies on the hydrogen bonding of aniline's derivatives by FT-IR.

Studies on Amide III Infrared Bands for the Secondary Structure Determination of Proteins

Mechanism of Interaction between Chrysin and Different Configurations of Human Serum Albumin