19 F NMR Chemical Shifts Induced by a Helical Peptide
| Autor: | Matthew A. Kubasik, Erin Daly, Adam Blom |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
chemistry.chemical_classification
Fluorine Radioisotopes Protein Conformation Chemistry Stereochemistry Chemical shift Static Electricity Organic Chemistry Peptide Nuclear magnetic resonance spectroscopy Dielectric Fluorine-19 NMR Magnetic Resonance Imaging Biochemistry NMR spectra database Structure-Activity Relationship Crystallography chemistry.chemical_compound Amide Molecular Medicine Molecule Oligopeptides Molecular Biology |
| Zdroj: | ChemBioChem. 7:1056-1061 |
| ISSN: | 1439-7633 1439-4227 |
| DOI: | 10.1002/cbic.200500541 |
| Popis: | (19)F NMR spectra of two neutral, organic-soluble helical peptide octamers, each labeled at its N terminus with either 4-fluorobenzamide or 4-trifluoromethylbenzamide, in solvents with widely varying dielectric constants have been observed. The peptides are oligomers of alpha-aminoisobutyric acid (Aib), which is a residue known to form stable 3(10) helices in organic solution. In relation to the (19)F NMR spectra of a control molecule, the peptide terminating in 4-fluorobenzamide shows a solvent-dependent downfield chemical shift of between approximately 1.5 and approximately 4 ppm, whilst the peptide terminating in 4-trifluoromethylbenzamide shows only an approximately 0.2 ppm chemical shift dependence on the solvent dielectric constant. The experimental observations were compared to calculated values of the electric field generated by the correlation of dipolar amide units through the peptide's helical conformation. We find the chemical-shift response of the 4-fluorobenzamide group to the peptide's calculated electric field is consistent with the magnitude of (19)F chemical shift dispersion observed in proteins. |
| Databáze: | OpenAIRE |
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