Comparison between UV Raman and Circular Dichroism Detection of Short α Helices in Bombolitin III
| Autor: | Sanford A. Asher, Abdil Ozdemir, Igor K. Lednev |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Circular dichroism
Chemistry Circular Dichroism Molecular Sequence Data Analytical chemistry Salt bridge (protein and supramolecular) Spectrum Analysis Raman Resonance (chemistry) Biochemistry Protein Structure Secondary Turn (biochemistry) Crystallography symbols.namesake Bombolitin III symbols Amino Acid Sequence Peptides Raman spectroscopy Protein secondary structure Alpha helix |
| Zdroj: | Biochemistry. 41:1893-1896 |
| ISSN: | 1520-4995 0006-2960 |
| DOI: | 10.1021/bi010970e |
| Popis: | We have used UV resonance Raman (UVRR) and circular dichroism (CD) spectroscopies to examine the dilute solution-phase secondary structure of the 17 amino acid peptide Bombolitin III (BIII). Both UVRR and CD clearly observe the alpha-helix structure induced by the addition of trifluoroethanol (TFE) to BIII. In contrast, only UVRR is able to detect the single alpha-helical turn induced by increasing the pH of BIII from pH 1.8 to 6.4. This alpha-helical turn is formed because of a stabilizing salt bridge formed between Lys(2) and Asp(5). Further increases in the alpha-helix content occur as the pH is raised further. We compare the relative sensitivity of UVRR and CD to short alpha helices and find, as expected, that the CD cannot detect short alpha helices. This study demonstrates that UV Raman measurements can detect the formation of single alpha-helical turns which cannot be detected by CD measurements. |
| Databáze: | OpenAIRE |
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