Journal article

Publication year: 2015

Pages: 1114-1117

Journal: Acta Crystallographica. Section C: Structural Chemistry

Volume number: 71

ISSN: 2053-2296

DOI Link: https://doi.org/10.1107/S2053229615022597

Publisher: Wiley

Abstract: 
Glycine (Gly) is incorporated in roughly half of all known peptaibiotic (nonribosomally biosynthesized antibiotic peptides of fungal origin) sequences and is the residue with the greatest conformational flexibility. The conformational space of Aib (alpha-aminoisobutyric acid) is severely restricted by the second methyl group attached to the C-alpha atom. Most of the crystal structures containing Aib are N-terminal protected. Deprotection of the N-or C-terminus of peptides may alter the hydrogen-bonding scheme and/or the structure and may facilitate crystallization. The structure reported here for glycyl-alpha-aminoisobutyrylglycyl-alpha-aminoisobutyric acid tert-butyl ester, C16H30N4O5, describes the first N-terminal-unprotected (Gly-Aib)(n) peptide. The achiral peptide could form an intramolecular hydrogen bond between the C=O group of Gly1 and the N-H group of Aib4. This hydrogen bond is found in all tetrapeptides and N-terminal-protected tripeptides containing Aib, apart from one exception. In the present work, this hydrogen bond is not observed (N center dot center dot center dot O = 5.88 angstrom). Instead, every molecule is hydrogen bonded to six other symmetry-related molecules with a total of eight hydrogen bonds per molecule. The backbone conformation starts in the right-handed helical region (and the left-handed helical region for the inverted molecule) and reverses the screw sense in the last two residues.

Harvard Citation style: Gessmann, R., Brueckner, H. and Petratos, K. (2015) The first N-terminal unprotected (Gly-Aib)n peptide: H-Gly-Aib-Gly-Aib-OtBu, Acta Crystallographica. Section C: Structural Chemistry, 71, pp. 1114-1117. https://doi.org/10.1107/S2053229615022597

APA Citation style: Gessmann, R., Brueckner, H., & Petratos, K. (2015). The first N-terminal unprotected (Gly-Aib)n peptide: H-Gly-Aib-Gly-Aib-OtBu. Acta Crystallographica. Section C: Structural Chemistry. 71, 1114-1117. https://doi.org/10.1107/S2053229615022597