Amyloid‐Like Fibrillogenesis through Supramolecular Helix‐Mediated Self‐Assembly of Tetrapeptides Containing Non‐Coded α‐Aminoisobutyric Acid (Aib) and 3‐Aminobenzoic Acid (m‐ABA) |
| |
| Authors: | Arpita Dutta Michael G. B. Drew Animesh Pramanik |
| |
| Affiliation: | 1. Department of Chemistry, University of Calcutta, 92 A.?P.?C. Road, Kolkata‐700?009, India, (phone: +91‐33‐24841647;2. fax: +91‐33‐23519755);3. School of Chemistry, The University of Reading, Whiteknights, Reading, RG6?6AD, UK |
| |
| Abstract: | Single‐crystal X‐ray diffraction studies of two terminally protected tetrapeptides Boc‐Ile‐Aib‐Val‐m‐ABA‐OMe ( I ) and Boc‐Ile‐Aib‐Phe‐m‐ABA‐OMe ( II ) (Aib=α‐aminoisobutyric acid; m‐ABA=meta‐aminobenzoic acid) reveal that they form continuous H‐bonded helices through the association of double‐bend (type III and I) building blocks. NMR Studies support the existence of the double‐bend (type III and I) structures of the peptides in solution also. Field emission scanning electron‐microscopic (FE‐SEM) and high‐resolution transmission electron‐microscopic (HR‐TEM) images of the peptides exhibit amyloid‐like fibrils in the solid state. The Congo red‐stained fibrils of peptide I and II , observed between crossed polarizers, show green‐gold birefringence, a characteristic of amyloid fibrils. |
| |
| Keywords: | Peptides Self‐assembly Helix α ‐Aminoisobutyric acid (Aib) Benzoic acid, 3‐amino‐ Amyloid‐like fibrils X‐Ray crystallography |
|
|
