Open AccessCyclized dipeptide model for a beta-bend.
Author(s) -
Roxanne Deslauriers,
Sydney Leach,
Frederick R. Maxfield,
E. Minasian,
J. R. McQuie,
Yvonne C. Meinwald,
George Némethy,
Marcia S. Pottle,
Ian D. Rae,
Harold A. Scheraga,
Evelyn R. Stimson,
J. W. van Nispen
Publication year - 1979
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.76.6.2512
Subject(s) - dipeptide , chemistry , molecule , hydrogen bond , crystallography , nuclear magnetic resonance spectroscopy , stereochemistry , raman spectroscopy , circular dichroism , resonance raman spectroscopy , peptide , organic chemistry , physics , biochemistry , optics
A cyclic dipeptide in which L-Ala-Gly was cyclized with epsilon-aminocaproic acid has been synthesized as a model for a beta-bend. Its conformational properties have been examined by means of conformational energy calculations and nuclear magnetic resonance, infrared, Raman, and circular dichroism spectroscopy in various solvents. These calculations and experiments suggest that a type II beta-bend exists in the Ala-Glymoiety, with an NH...O = C hydrogen bond in the epsilon-aminocaproic acid portion of the molecule, and that the molecule adopts a unique conformation in solution. In contrast, an open-chain analog of this compound exists in solution as an ensemble of conformations but with a significant amount of a type II beta-bend structure in the ensemble.