A Novel Long-Range n to π* Interaction Secures the Smallest known α-Helix in Water.
Angew Chem Int Ed Engl
; 58(52): 18873-18877, 2019 12 19.
Article
in En
| MEDLINE
| ID: mdl-31625253
ABSTRACT
The introduction of an amide bond linking side chains of the first and fifth amino acids forms a cyclic pentapeptide that optimally stabilizes the smallest known α-helix in water. The origin of the stabilization is unclear. The observed dependence of α-helicity on the solvent and cyclization linker led us to discover a novel long-range n to π* interaction between a main-chain amide oxygen and a uniquely positioned carbonyl group in the linker of cyclic pentapeptides. CD and NMR spectra, NMR and X-ray structures, modelling, and MD simulations reveal that this first example of a synthetically incorporated long-range n to π* COâ
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Cγ =Ο interaction uniquely enforces an almost perfect and remarkably stable peptide α-helix in water but not in DMSO. This unusual interaction with a covalent amide bond outside the helical backbone suggests new approaches to synthetically stabilize peptide structures in water.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Angew Chem Int Ed Engl
Year:
2019
Type:
Article
Affiliation country:
Australia