The crystal structure of Afc-containing peptides

✍ Scribed by Angela Lombardi; Giuseppina De Simone; Stefania Galdiero; Flavia Nastri; Luigi Di Costanzo; Kazunari Makihira; Takashi Yamada; Vincenzo Pavone

• Publisher: Wiley (John Wiley & Sons)
• Year: 2000
• Tongue: English
• Weight: 237 KB
• Volume: 53
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/(sici)1097-0282(200002)53:2<150::aid-bip5>3.0.co;2-c

✦ Synopsis

A systematic structural analysis of Afc (9-amino-fluorene-9-carboxylic acid) containing peptides is here reported. The crystal structures of four fully protected tripeptides containing the Afc residue in position 2: Z-X 1 -Afc 2 -Y 3 -OMe (peptide a: X ϭ Y ϭ Gly; peptide b: X ϭ Aib, C ␣,␣ -dimethylglycine, Y ϭ Gly; peptide c: X ϭ Gly, Y ϭ Aib; peptide d: X ϭ Y ϭ Aib) have been solved by x-ray crystallography. All the results suggest that the Afc residue has a high propensity to assume an extended conformation. In fact, the Afc residue adopts an extended conformation in three peptides examined in this paper (peptides a-c). In contrast, Afc was found in a folded conformation, in the 3 10 -helical region, only in the peptide d, in which it is both preceded and followed by the strong helix promoting Aib.