Self-assembling tripeptide as organogelator: the role of aromatic π-stacking interactions in gel formation
摘要:
While the terminally protected tripeptide Boc-Phe-Gly-m-ABA-OMe I (m-ABA, meta-amino benzoic acid) is an excellent gelator of aromatic organic solvents, another similar tripeptide Boc-Leu-Gly-m-ABA-OMe II, where the Phe residue of peptide I is replaced by Leu, cannot form gels with the same solvents. The morphology of the gels of peptide I, characterised by the field-emission scanning electron microscopy and high-resolution transmission electron microscopy, reveals the formation of nanofibrous networks which are known to encapsulate solvent molecules to form gels. The wide-angle X-ray scattering studies of the gels suggest the beta-sheet-mediated self-assembly of peptide I in the formation of a nanofibrous network, where pi-stacking interactions of Phe play an important role in the self-assembly and gel formation. The dried gel of peptide I observed between crossed polarisers after binding with a physiological dye, Congo red, shows a bluish-green birefringence, a characteristic of amyloid fibrils.
Studies of Amyloid-Like Fibrillogenesis through<i>β</i>-Sheet-Mediated Self-Assembly of Short Synthetic Peptides
作者:Anita Dutt、Elinor C. Spencer、Judith A. K. Howard、Animesh Pramanik
DOI:10.1002/cbdv.200900050
日期:2010.2
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