Molecular Interaction between SoyasaponinⅡand Bovine Serum Albumin Determined by Spectrometric and Molecular Modeling Methods

Abstract:

Intrinsic fluorescence spectrometry，circular dichroism spectrometry and molecular modeling methods were used to investigate the interaction between soyasaponin II and bovine serum albumin（BSA）. Results showed that the adding of soyasaponin II caused the fluorescence quenching and a decrease of the maximum emission wavelength，leading to the increase of hydrophobicity around tryptophan and the change of tertiary structure of BSA. The binding of soyasaponin II also reduced the negative ellipticity of circular dichroism spectra，unfolded the peptide chain and changed the secondary structure of BSA. Molecular docking revealed a good binding of soyasaponin II to BSA，with arabinopyranosyl and rhamnopyranosyl parts of the sugar chain forming hydrogen bonds with Asp108，Asp111，Arg144 and Arg458，and the aglycone moiety interacting with 15 amino acids by hydrophobic interaction.