Structural analyses of isolated cyclic tetrapeptides with varying amino acid residues
| Autor: | Astrid Schaly, Anke Stamm, Julia Bartl, S. Schlicher, Stefan Kubik, Dominique Maué, Markus Gerhards |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
chemistry.chemical_classification
010405 organic chemistry Hydrogen bond Stereochemistry Spectrum Analysis General Physics and Astronomy Hydrogen Bonding Peptide 010402 general chemistry Ring (chemistry) Peptides Cyclic 01 natural sciences Protein Structure Secondary Cyclic peptide 0104 chemical sciences chemistry.chemical_compound chemistry Side chain Amino Acid Sequence Carboxylate Amino Acids Physical and Theoretical Chemistry Dispersion (chemistry) Peptide sequence Protein Binding |
| Zdroj: | Physical Chemistry Chemical Physics. 19:10718-10726 |
| ISSN: | 1463-9084 1463-9076 |
| DOI: | 10.1039/c6cp08696a |
| Popis: | Cyclic peptides represent a large class of substances that occur in nature with important biological and medical functions. Synthetic cyclic peptides are used as artificial receptors due to a series of advantages over conventional receptors. In order to optimize their binding abilities, investigations of their intrinsic structural properties especially with regard to the influence of different amino acid residues are fundamental. Here we report the structural analysis of two synthetic cyclic tetrapeptides cyclo[L-Tyr(Me)-D-Pro-L-Ala-D-Pro] (CPAla) and cyclo[L-Tyr(Me)-D-Pro-L-Glu(Me)-D-Pro] (CPGlu) in a molecular beam by means of combined IR/UV spectroscopic techniques. Structural assignments were achieved by comparing experimentally obtained vibrations and harmonically calculated frequencies including dispersion corrections (B3LYP-D3/TZVP). The investigated cyclic peptides contain an arrangement of an amino acid sequence which is no longer symmetric compared to the former investigations of the cyclo[L-Tyr(Me)-D-Pro]2 peptide. It turns out that all investigated compounds prefer conformations stabilized by two internal hydrogen bonds. In the case of CPGlu containing a flexible side chain with a terminal hydrogen bond acceptor an additional structure was observed in which a hydrogen bond between the terminal carboxylate group and a ring NH group is formed. |
| Databáze: | OpenAIRE |
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