Crystal state conformation of three model monomer units for the β-bend ribbon structure

✍ Scribed by G. Valle; R. Bardi; A. M. Piazzesi; M. Crisma; C. Toniolo; G. Cavicchioni; K. Uma; P. Balaram

• Publisher: Wiley (John Wiley & Sons)
• Year: 1991
• Tongue: English
• Weight: 470 KB
• Volume: 31
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.360311402

✦ Synopsis

Abstract

The molecular and crystal structures of three compounds, representing the repeating units of the β‐bend ribbon (an approximate 3~10~‐helix, with an intramolecular hydrogen‐bonding donor every two residues), have been determined by x‐ray diffraction. They are Boc‐Aib‐Hib‐NHBzl, Z‐Aib‐Hib‐NHBzl, and Z‐L‐Hyp‐Aib‐NHMe (Aib, α‐aminoisobutyric acid; Bzl, benzyl; Boc, t‐butyloxycarbonyl; Hyp, hydroxyproline Hib, α‐hydroxyisobutyric acid; Z, benzyloxycarbonyl). The two former compounds are folded in a β‐bend conformation: type III (III′) for Boc‐Aib‐Hib‐NHBzl, while type II (II′) for the Z analogue. Conversely, the structure of Z‐L‐Hyp‐Aib‐NHMe, although not far from a type II β‐bend, is partially open.