A nanofiber assembly directed by the non-classical antiparallel β-structure from 4S-(OH) proline polypeptide

Abstract

The antiparallel arrangement of two strands of the non-classical β-structure, formed exclusively via cis-4S-(OH) prolyl polypeptide as established by FRET, propagates into self-assembled nanofibers upon conjugation with C12/C14/C16 hydrocarbon chains.

Stereodependent and solvent‐specific formation of unusual β‐structure through side chain‐backbone H‐bonding in C4(S)‐(NH2/OH/NHCHO)‐L‐prolyl polypeptides

“…Here we conjecture that the two chains in β‐structure may have similar dihedral angles as in PPII conformation, and β‐structure may arise from hydrogen bonding between side chain (OH/NH) groups of one chain and the backbone carbonyl oxygen of another chain. We emphasize that the present results do not provide any direct experimental evidences for the microstructural details of proline pucker, amide bond geometry or the exact hydrogen bonding patterns, but the antiparallel orientation of the two chains of β‐structure is evident from our recent work …”

“…The proposed β‐structure here (Figure B) is unusual in the sense that it originates from H‐bonding of acceptor carbonyl amide on backbone with the side chain donor amino group on the opposite chain. By employing FRET and FESEM, we have recently shown that the orientation of two strands of β‐structure in (4 S )‐ Hyp 9 is antiparallel . In this orientation, by retaining the C4‐ endo pucker, C4( S )‐NH 2 /OH/NHCHO peptides can in principle form both interchain and intraresidue H‐bonds, (Figure B,D).…”

“…By employing FRET and FESEM, we have recently shown that the orientation of two strands of b-structure in (4S)-Hyp 9 is antiparallel. [29] In this orientation, by retaining the C4-endo pucker, An ideal PPII helix has dihedral angles u and w of 2758 and 11458, respectively, and all amide bonds are in trans conformations (x 5 1808). [12] Here we conjecture that the two chains in b-structure may have similar dihedral angles as in PPII conformation, and b-structure may arise from hydrogen bonding between side chain (OH/NH) groups of one chain and the backbone carbonyl oxygen of another chain.…”

Exploring hydrophobicity limits of polyproline helix with oligomeric octahydroindole‐2‐carboxylic acid

“…Alternatively, isomerization of P II helix can proceed into a nonclassical backbone‐side chain hydrogen‐bonded β‐sheet‐like assemblies (in trifluoroethanol). The latter were documented only very recently for peptides formed by specific proline analogues …”

Solvation driven conformational transitions in the second transmembrane domain of mycobacteriophage holin

“…4,[13][14][15] However, segments that adopt PPII-like structures have been observed in short polypeptides and proteins. [16][17][18][19] PPII-like segments with a minimum of length two residues and a maximum of 14 residues has been observed to date. 16,20 While Pro-rich regions show a preference for the PPII structure, host-guest based analysis using Pro-containing sequences as the host revealed that when Gln, Asp, Gly, and Ala (guest) are incorporated, the guest residues can adopt the PPII form.…”