ISBN: 978-83-60043-10-3 - eurobic9

Eurobic9, 2-6 September, 2008, Wrocław, Poland
O24. The Influence of Metal Cation Binding to Aromatic Side Chain on
Hydrogen Bond System in Alpha Helical Peptides
R. Wieczorek
Department of Chemistry, University of Wroclaw, Poland.
The secondary structure of proteins depends on fragile equilibrium between non-covalent intra and
intermolecular interactions between protein and solvent/soluted compounds. The common motifs of peptides –
alpha helical peptides have been explored both experimentally and theoretically [1-4]. The modern
computational chemistry methods allow to investigate selected effect e.g. interaction between side chain and ions
present in solvent. The alpha helical peptides contain three chain-organized hydrogen bond groups. The
interaction between aromatic side chain and small cation influence on helix by strong modification of hydrogen
bonds. The ion – peptide interaction significantly changes stability of the peptide.
Acknowledgement: Polish Ministry of Science and Higher Education, grant number: N N204 216834.
References:
[1]. Z. Shi, C. A. Olson, G. D. Rose, R. L. Baldwin, and N. R. Kallenbach "Polyproline II structure in a sequence
of seven alanine residues", Proc. Nat. Acad. Sci. 2002; 99: 9190-9195
[2]. Wallimann P., Kennedy R.J., Miller J.S., Shalongo W., Kemp D.S. "Dual wavelength parametric test of twostate
models for circular dichroism spectra of helical polypeptides: anomalous dichroic properties of alanine-rich
peptides", J. Am. Chem. Soc. 2003;125:1203–1220
[3]. Wieczorek R. and Dannenberg J.J. "The Energetic and Structural Effects of Single Amino Acid
Substitutions upon Capped r-Helical Peptides Containing 17 Amino Acid Residues. An ONIOM DFT/AM1
Study", J. Am. Chem. Soc. 2005; 127: 17216-17223
[4]. Salvador P., Wieczorek R. and Dannenberg J.J. "Direct Calculation of trans-Hydrogen-Bond 13C-15N 3-
Bond J-Couplings in Entire Polyalanine alpha-Helices. A Density Functional Theory Study", J. Phys. Chem. B
2007; 111: 2398-2403
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