Polyphenols and Alzheimer's Disease: Tau/polyphenol interactions investigated by NMR and molecular modelling

Abstract

Tau that belongs to the family of microtubule-associated proteins is the major constituent of intraneuronal fibrillar lesions described in Alzheimer's Disease (AD). Its sequence homology with salivary proline-rich proteins (sPRP), known to fix tannins, combined with some epidemiological evidences that a moderate consumption of polyphenols presents benefits in AD, suggests that tannins can bind Tau protein and, perhaps, could inhibit or modulate the cascade of events leading to AD symptoms. To study the affinity of tannins towards the Tau proline rich domain P2, we have first synthesized a peptide representative of this domain, determined its 3D-structure and its affinity towards different procyanidins (epicatechin-EC, epicatechin gallate-ECG, epigallocatechin gallate-EGCG and procyanidin B3 and B2) by using both NMR, molecular modelling and dynamic techniques. We have found that the Tau peptide is able to fix the different tested tannins in two distinct domains with an affinity in the mM range.