C-9/12 Ribbon-Like Structures in Hybrid Peptides Alternating - and Thiazole-Based -Amino Acids
According to their restricted conformational freedom, heterocyclic -amino acids are usually considered to be related to Z-vinylogous -amino acids. In this context, oligomers alternating -amino acids and thiazole-based -amino acids (ATCs) were expected to fold into a canonical 12-helical shape as des...
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Published in | Chemistry : a European journal Vol. 23; no. 69; pp. 17584 - 17591 |
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Main Authors | , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
WEINHEIM
Wiley
11.12.2017
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Subjects | |
Online Access | Get full text |
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Summary: | According to their restricted conformational freedom, heterocyclic -amino acids are usually considered to be related to Z-vinylogous -amino acids. In this context, oligomers alternating -amino acids and thiazole-based -amino acids (ATCs) were expected to fold into a canonical 12-helical shape as described for /-hybrid peptides composed of cis-/-unsaturated -amino acids. However, through a combination of X-ray crystallography, NMR spectroscopy, FTIR experiments, and DFT calculations, it was determined that the folding behavior of ATC-containing hybrid peptides is much more complex. The homochiral /(S)-ATC sequences were unable to adopt a stable conformation, whereas the heterochiral /(R)-ATC peptides displayed novel ribbon structures stabilized by unusual C-9/12-bifurcated hydrogen bonds. These ribbon structures could be considered as a succession of pre-organized / dipeptides and may provide the basis for designing original -helix mimics. |
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ISSN: | 0947-6539 1521-3765 |
DOI: | 10.1002/chem.201704001 |