The N-terminal half of a mitochondrial presequence peptide inserts into cardiolipin-containing membranes. Consequences for the action of a transmembrane potential.
The orientation of a mitochondrial-presequence peptide, associated with anionic lipid-containing model membranes, was investigated. The peptide inserts with its N-terminal alpha-helical part into cardiolipin (CL) monolayers so that the N-terminal 14 residues are protected from proteinase K. In phosphatidylglycerol (PG) monolayers the inserted peptide was fully accessible to the protease. A consequence of the different orientations of the peptide was that membrane potential-dependent protection from trypsin was much faster for the peptide bound to PG-containing vesicles compared to CL-containing membranes, suggesting that in the mitochondrial protein import process other components of the import apparatus are involved in the efficient potential-driven translocation of presequences across the inner mitochondrial membranes.
Leenhouts
J M
JM
Department of Biochemistry of Membranes, Centre for Biomembranes and Lipid Enzymology, Institute of Biomembranes, Utrecht University, The Netherlands.
Török
Z
Z
Mandieau
V
V
Goormaghtigh
E
E
de Kruijff
B
B
D000595:Amino Acid Sequence; D002308:Cardiolipins / Q000737:chemistry*; D003576:Electron Transport Complex IV / Q000737:chemistry*; D019286:Endopeptidase K; D004792:Enzyme Precursors / Q000737:chemistry*; D008563:Membrane Lipids / Q000737:chemistry*; D008564:Membrane Potentials; D008928:Mitochondria / Q000737:chemistry*; D008969:Molecular Sequence Data; D010715:Phosphatidylglycerols / Q000737:chemistry; D021382:Protein Sorting Signals / Q000737:chemistry*; D017421:Sequence Analysis; D012697:Serine Endopeptidases; D014357:Trypsin
D002308:Cardiolipins; D004792:Enzyme Precursors; D008563:Membrane Lipids; D010715:Phosphatidylglycerols; D021382:Protein Sorting Signals; D003576:Electron Transport Complex IV; D012697:Serine Endopeptidases; D014357:Trypsin; D019286:Endopeptidase K