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NMR and molecular modeling of wine tannins binding to saliva proteins: revisiting astringency from molecular and colloidal prospects.
- Source :
-
FASEB journal : official publication of the Federation of American Societies for Experimental Biology [FASEB J] 2010 Nov; Vol. 24 (11), pp. 4281-90. Date of Electronic Publication: 2010 Jul 06. - Publication Year :
- 2010
-
Abstract
- In organoleptic science, the association of tannins to saliva proteins leads to the poorly understood phenomenon of astringency. To decipher this interaction at molecular and colloidal levels, the binding of 4 procyanidin dimers (B1-4) and 1 trimer (C2) to a human saliva proline-rich peptide, IB7(14), was studied. Interactions have been characterized by measuring dissociation constants, sizes of complexes, number, and nature of binding sites using NMR (chemical shift variations, diffusion-ordered spectroscopy, and saturation transfer diffusion). The binding sites were identified using molecular mechanics, and the hydrophilic/hydrophobic nature of the interactions was resolved by calculating the molecular lipophilicity potential within the complexes. The following comprehensive scheme can be proposed: 1) below the tannin critical micelle concentration (CMC), interaction is specific, and the procyanidin anchorage always occurs on the same three IB7(14) sites. The tannin 3-dimensional structure plays a key role in the binding force and in the tannin's ability to act as a bidentate ligand: tannins adopting an extended conformation exhibit higher affinity toward protein and initiate the formation of a network. 2) Above the CMC, after the first specific hydrophilic interaction has taken place, a random hydrophobic stacking occurs between tannins and proteins. The whole process is discussed in the general frame of wine tannins eliciting astringency.
- Subjects :
- Antioxidants chemistry
Antioxidants metabolism
Biflavonoids chemistry
Biflavonoids metabolism
Catechin chemistry
Catechin metabolism
Colloids chemistry
Dimerization
Humans
Molecular Dynamics Simulation
Molecular Structure
Proanthocyanidins chemistry
Proanthocyanidins metabolism
Protein Binding
Salivary Proteins and Peptides chemistry
Astringents
Magnetic Resonance Spectroscopy
Models, Molecular
Salivary Proteins and Peptides metabolism
Tannins chemistry
Tannins metabolism
Wine
Subjects
Details
- Language :
- English
- ISSN :
- 1530-6860
- Volume :
- 24
- Issue :
- 11
- Database :
- MEDLINE
- Journal :
- FASEB journal : official publication of the Federation of American Societies for Experimental Biology
- Publication Type :
- Academic Journal
- Accession number :
- 20605948
- Full Text :
- https://doi.org/10.1096/fj.10-158741