N-terminal half of a mitochondrial presequence peptide takes a helical conformation when bound to dodecylphosphocholine micelles: a proton nuclear magnetic resonance study.
Two-dimensional proton nuclear magnetic resonance (NMR) spectra of a synthetic peptide (p25) corresponding to the amino-terminus of the yeast mitochondrial cytochrome oxidase subunit IV precursor protein have been analyzed. Sequence-specific resonance assignments of the peptide have been made in the presence of micelles of a phospholipid analog, perdeuterated dodecylphosphocholine (DPC), with the aid of such techniques as HOHAHA, DQF-COSY, and NOESY. The interresidue nuclear Overhauser effects (NOEs) indicate that the N-terminal half of p25 (S3-F11) takes a helical structure while the C-terminal half does not take a regular secondary structure. Addition of DPC to the solution of p25 induced chemical shift changes only of the resonances from the residues in the N-terminal half, suggesting that the N-terminal half of p25 is directly involved in binding to DPC. The induced helical structure in the N-terminal half at a lipid-water interface may be important in the ability of this presequence to direct a "passenger" protein into mitochondria.
Endo
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Department of Chemistry, College of Technology, Gunma University.
Shimada
I
I
Roise
D
D
Inagaki
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F
D002794:Choline / Q000031:analogs & derivatives*; D003576:Electron Transport Complex IV / Q000032:analysis / Q000378:metabolism* / Q000502:physiology; D004792:Enzyme Precursors / Q000032:analysis / Q000378:metabolism* / Q000502:physiology; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008823:Micelles; D008928:Mitochondria / Q000201:enzymology; D008958:Models, Molecular; D010767:Phosphorylcholine / Q000031:analogs & derivatives* / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D021382:Protein Sorting Signals / Q000032:analysis / Q000378:metabolism* / Q000502:physiology
D004792:Enzyme Precursors; D008823:Micelles; D021382:Protein Sorting Signals; D010767:Phosphorylcholine; C028810:dodecylphosphocholine; D003576:Electron Transport Complex IV; D002794:Choline