Solid-state NMR analysis of interaction sites of curcumin and 42-residue amyloid ?-protein fibrils.

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Solid-state NMR analysis of interaction sites of curcumin and 42-residue amyloid ?-protein fibrils.

Solid-state NMR analysis of interaction sites of curcumin and 42-residue amyloid ?-protein fibrils.

Bioorg Med Chem. 2011 Aug 27;

Authors: Masuda Y, Fukuchi M, Yatagawa T, Tada M, Takeda K, Irie K, Akagi KI, Monobe Y, Imazawa T, Takegoshi K

Abstract
Aggregation of 42-residue amyloid ?-protein (A?42) plays a pivotal role in the etiology of Alzheimer's disease (AD). Curcumin, the yellow pigment in the rhizome of turmeric, attracts considerable attention as a food component potentially preventing the pathogenesis of AD. This is because curcumin not only inhibits the aggregation of A?42 but also binds to its aggregates (fibrils), resulting in disaggregation. However, the mechanism of interaction between curcumin and the A?42 fibrils remains unclear. In this study, we analyzed the binding mode of curcumin to the A?42 fibrils by solid-state NMR using dipolar-assisted rotational resonance (DARR). To improve the quality of 2D spectra, 2D DARR data were processed with the covariance NMR method, which enabled us to detect weak cross peaks between carbons of curcumin and those of the A?42 fibrils. The observed (13)C-(13)C cross peaks indicated that curcumin interacts with the 12th and 17-21st residues included in the ?-sheet structure in the A?42 fibrils. Interestingly, aromatic carbons adjacent to the methoxy and/or hydroxy groups of curcumin showed clear cross peaks with the A?42 fibrils. This suggested that these functional groups of curcumin play an important role in its interaction with the A?42 fibrils.


PMID: 21924918 [PubMed - as supplied by publisher]



Source: PubMed