The crystal structure of Z-(Aib)10-OH at 0.65 Å resolution: three complete turns of 310-helix

DOI: 10.1002/psc.2842
PMID: 26680663

Authors: Renate Gessmann (IMBB/FORTH) , Hans Brückner (Justus-Liebig-University of Giessen) , Kyriacos Petratos (IMBB-FoRTH)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Peptide Science , VOL 22

State: Published (Approved)
Published: January 2016
Diamond Proposal Number(s): 13200

Abstract: The synthetic peptide Z-(Aib)10-OH was crystallized from hot methanol by slow evaporation. The crystal used for data collection reflected synchrotron radiation to sub-atomic resolution, where the bonding electron density becomes visible between the non-hydrogen atoms. Crystals belong to the centrosymmetric space group P-1 inline image. Both molecules in the asymmetric unit form regular 310-helices. All residues in each molecule possess the same handedness, which is in contrast to all other crystal structure determined to date of longer Aib-homopeptides. These other peptides are C-terminal protected by OtBu or OMe. In these cases, because of the missing ability of the C-terminal protection group to form a hydrogen bond to the residue i-3, the sense of the helix is reversed in the last residue. Here, the C-terminal OH-groups form hydrogen bonds to the residues i-3, in part mediated by water molecules. This makes Z-(Aib)10-OH an Aib-homopeptide with three complete 310-helical turns in spite of the shorter length it has compared with Z-(Aib)11-OtBu, the only homopeptide to date with three complete turns.

Journal Keywords: α-aminoisobutyric acid; 310-helix; sub-atomic resolution; centrosymmetry; achiral peptide; left-handed helix; unprotected peptide; three complete turns

Subject Areas: Chemistry, Biology and Bio-materials


Instruments: I24-Microfocus Macromolecular Crystallography

Added On: 03/01/2016 16:17

Discipline Tags:

Biochemistry Chemistry Structural biology Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)