First homo-peptides undergoing a reversible 310-helix/α-helix transition: Critical main-chain length
✍ Scribed by Alessandro Moretto; Fernando Formaggio; Bernard Kaptein; Quirinus B. Broxterman; Ling Wu; Timothy A. Keiderling; Claudio Toniolo
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 2008
- Tongue
- English
- Weight
- 183 KB
- Volume
- 90
- Category
- Article
- ISSN
- 0006-3525
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✦ Synopsis
Abstract
The difference in length between the more elongated peptide 3~10~‐helix and the more compact α‐helix is about 0.4 Å/residue. This property makes the 3~10~‐/α‐helix reversible conversion very promising as a molecular switching tool between the N‐ and C‐terminal functions of a peptide backbone. In this work, using homo‐peptides of various main‐chain length, all based on the strongly helicogenic, C^α^‐tetrasubstituted α‐amino acid C^α^‐methyl‐L‐valine, we show that a well defined, solvent controlled, reversible 3~10~‐/α‐helix transition takes place even in a homo‐oligomer as short as a terminally blocked hexapeptide. Homo‐peptide sequences blocked as a urethane or an acetamide at the N‐terminus and as a methyl ester or an N‐alkyl amide at the C‐terminus are all appropriate. The nature of the occurring helical species in the various solvents tested was assessed by electronic or vibrational circular dichroism. © 2008 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90: 567–574, 2008.
This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at [email protected]