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Updated: Aug 2, 2026
Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
Hydrogen-bond cooperativity, vibrational coupling, and dependence of helix stability on changes in amino acid
Robert Wieczorek1, J J Dannenberg
1Department of Chemistry, City University of New York, Hunter College and the Graduate School, 695 Park Avenue, New York, NY 10021, USA.
Abstract:
Five pentapeptides, GGGGG, GAGGG, GVGGG, GLGGG, and GIGGG, have been completely optimized in the 3(10)-helical and open beta-strand conformations at the B3LYP/D95 level. The energies of the helices relative to the beta-strands vary from -2.1 to -3.6 kcal and depend on the amino acid residue sequence. The energies of substituting A, V, L, or I for G in the second position are also presented. Vibrational analyses were performed on the optimized structures. Vibrational coupling through the individual H-bond chains of the helices is confirmed to be stronger than that through space or through the covalent bonds. The cooperative interactions of the H-bonds are evident from both the structures and the coupling of the amide I, amide II, and N-H vibrations.
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