Secondary Structure and Topology of a Mitochondrial Presequence Peptide Associated with Negatively Charged Micelles. A 2D 1H-NMR Study
Autor: | Johanna M. Leenhouts, Vladimir Chupin, Ben de Kruijff, and Anton I. P. M. de Kroon |
---|---|
Rok vydání: | 1996 |
Předmět: | |
Zdroj: | Biochemistry. 35:3141-3146 |
ISSN: | 1520-4995 0006-2960 |
Popis: | In this study the secondary structure and topology of the peptide, corresponding to the presequence of cytochrome oxidase subunit IV (p25) in a negatively charged membrane-mimetic environment, were assessed by circular dichroism and two-dimensional nuclear magnetic resonance. The micelles used consisted of dodecylphosphoglycol (DPG), a mild anionic detergent with a headgroup resembling that of phosphatidylglycerol. The secondary structure was analyzed by interresidue nuclear Overhauser enhancement measurements and chemical shifts of backbone protons. The data revealed alpha-helix formation of the peptide upon interaction with the micelles, both in the N- and in the C-terminal halves, which are separated from each other by the proline residue at position 13. The topology of the peptide was studied by determining the effect of spin-labeled 12-doxylstearate on the line widths of the peptide proton resonances. This method revealed the insertion of hydrophobic residues of both the N- and the C-terminal halves of p25 into the hydrophobic environment of the micelles, demonstrating the orientation of the amphiphilic helix. |
Databáze: | OpenAIRE |
Externí odkaz: |