Publications (2)1.8 Total impact
Article: Studies of amyloid-like fibrillogenesis through beta-sheet-mediated self-assembly of short synthetic peptides.[show abstract] [hide abstract]
ABSTRACT: Three structurally different types of small peptides, namely, i) Boc-Ile-Aib-Ile-OMe (Aib=alpha-aminoisobutyric acid), ii) Boc-Xx-m-aminobenzoic acid (Xx=beta-Ala and gamma-aminobutyric acid), and iii) Boc-Xx-m-nitroaniline, were found to exhibit beta-sheet-mediated fibrillogenesis in the solid state, revealed by FT-IR, single-crystal X-ray diffraction, and FE-SEM studies. Interestingly, the fibrils grown from peptides 2 and 3 were found to bind with the physiological dye Congo red, a characteristic feature of amyloid fibrils.Chemistry & Biodiversity 02/2010; 7(2):363-75. · 1.80 Impact Factor
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ABSTRACT: Single crystal X-ray diffraction studies show that among the three terminally protected model tripeptides I–III, Boc-Ile-Aib-Xx–OMe (Xx in peptide I: Val; II: Leu; III: Phe) with a centrally placed non-coded amino acid Aib (Aib: α-amino isobutyric acid), peptide I displays a conformational preference for β-turn, peptide II forms a hydrated β-turn representing the solvent mediated intermediate for the interconversion between β-turn and β-strand and peptide III adopts a completely unfolded β-strand like structure. By varying the steric bulk of the third residue, Xx(3), various conformations related to the structural interconversion between the β-turn and β-strand have been isolated. The peptide conformations in the solution phase have been probed by solvent dependent NMR titration and CD spectroscopy. Morphological studies with scanning electron microscopy (SEM) reveal that among the three peptides only peptide III can form filamentous fibrils in the solid state.Graphical abstractTetrahedron. 63(41):10282-10289.