Alcohol-Induced Conformation Changes and Thermodynamic Signatures in the Binding of Polyphenols to Proline-Rich Salivary Proteins.
Chemistry
; 29(67): e202302384, 2023 Dec 01.
Article
em En
| MEDLINE
| ID: mdl-37695254
ABSTRACT
The first contact of polyphenols (tannins) with the human body occurs in the mouth, where they are known to interact with proline-rich proteins (PRPs). These interactions are important at a sensory level, especially for the development of astringency, but affect also various other biochemical processes. Employing thermodynamic measurements, fluorescence and CD spectroscopy, we investigated the binding process of the prototypical polyphenol ellagic acid (EA) to different IB-PRPs and BSA, also in the presence of ethanol, which is known to influence tannin-protein interactions. Binding of EA to BSA and the small peptide IB7-14 is weak, but very strong to IB9-37. The differences in binding strength and stoichiometry are due to differences in the binding motifs, which also lead to differences in the thermodynamic signatures of the binding process. EA binding to BSA is enthalpy-driven, whereas binding to both IB7-14 and IB9-37 is entropy-driven. The presence of 10â
vol.% EtOH, as present in wines, increases the binding constant of EA with BSA and IB7-14 drastically, but not that with IB9-37; however, it changes the binding stoichiometry. These differences can be attributed to the effect of EtOH on the conformation dynamics of the proteins and to changes in hydration properties in alcoholic solution.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Prolina
/
Polifenóis
Limite:
Humans
Idioma:
En
Revista:
Chemistry
Assunto da revista:
QUIMICA
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Alemanha