beta-Sheet mediated self-assembly of dipeptides of omega-amino acids and remarkable fibrillation in the solid state

Dutt, A., Drew, M.G.B. and Pramanik, A. (2005) beta-Sheet mediated self-assembly of dipeptides of omega-amino acids and remarkable fibrillation in the solid state. Organic & Biomolecular Chemistry, 3 (12). pp. 2250-2254. ISSN 1477-0520 doi: 10.1039/b504112k

Abstract/Summary

Single crystal X-ray diffraction studies show that the extended structure of dipeptide I Boc-beta-Ala-m-ABA-OMe (m-ABA: meta-aminobenzoic acid) self-assembles in the solid state by intermolecular hydrogen bonding to create an infinite parallel P-sheet structure. In dipeptide II Boc-gamma-Abu-m-ABA-OMe (gamma-Abu: gamma-aminobutyric acid), two such parallel beta-sheets are further cross-linked by intermolecular hydrogen bonding through m-aminobenzoic acid moieties. SEM (scanning electron microscopy) studies reveal that both the peptides I and II form amyloid-like fibrils in the solid state. The fibrils are also found to be stained readily by Congo red, a characteristic feature of the amyloid fiber whose accumulation causes several fatal diseases such as Alzheimer's, prion-protein etc.