Stereochemistry of peptides containing 1-aminocyclopentanecarboxylic acid (Acc5): Solution and solid-state conformations of Boc-Acc5-Acc5-NHMe
✍ Scribed by R. Bardi; A. M. Piazzesi; C. Toniolo; M. Sukumar; P. Balaram
- Book ID
- 102765998
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1986
- Tongue
- English
- Weight
- 507 KB
- Volume
- 25
- Category
- Article
- ISSN
- 0006-3525
No coin nor oath required. For personal study only.
✦ Synopsis
The conformational analysis of a protected homodipeptide of 1-aminocyclopentanecarboxylic acid (Acc5) has been carried out. 'H-nmr studies establish a p-turn conformation for Boc-Acc'. Acc'-NHMe in chloroform and dimethylsulfoxide solutions involving the methylamide NH in an intramolecular hydrogen bond. Supportive evidence for the formation of an intramolecular hydrogen bond is obtained from ir studies. X-ray diffraction studies reveal a type I11 p-turn conformation in the solid state stabilized by B 4 + 1 hydrogen bond between the Boc CO and methylamide NH groups. The +, + values for both Ace5 residues are close to those expected for an ideal 3,,,-helical conformation ( $ = f60", + = k30").