Secondary structure of a mitochondrial signal peptide in lipid bilayer membranes |
| |
| Authors: | L K Tamm I Bartoldus |
| |
| Affiliation: | Department of Biophysical Chemistry, University of Basel, Switzerland. |
| |
| Abstract: | The secondary structure of the synthetic signal peptide of cytochrome c oxidase subunit IV (coxIV-25) has been measured by circular dichroism spectroscopy in different lipid environments. CoxIV-25 is polymorphic in membranes. It forms an amphiphilic alpha-helix both in negatively charged lipid bilayers (up to 49% helix) and in detergent micelles (up to 42% helix). In association with bilayers of the zwitterionic lipid phosphatidylcholine, coxIV-25 takes an aperiodic, unidentified structure. CoxIV-25 is also partially alpha-helical in bilayers of cardiolipin, mitochondrial lipid extracts and mixtures of synthetic phosphatidylcholine and phosphatidylglycerol. |
| |
| Keywords: | |
|
|
