Cytochrome c binds to lipid domains in arrays of mitochondrial outer membrane channels.
Computer-averaged electron microscopic images of negatively stained crystalline arrays of fungal mitochondrial outer-membrane channels in the presence and absence of cytochrome c were compared. Neither the apo- nor the holo- forms of cytochrome c significantly changed the stain distribution in the protein regions of the channel arrays. However, both forms of cytochrome c caused significant stain exclusion from the lipid domains in the arrays, suggesting binding of the polypeptides at these loci. The implications of binding of apocytochrome c to clusters of exposed phospholipids on the mitochondrial outer membrane are discussed with respect to the mechanism of uptake of this polypeptide by mitochondria.
D003198:Computer Simulation; D003574:Cytochrome c Group / Q000378:metabolism*; D007425:Intracellular Membranes / Q000378:metabolism* / Q000648:ultrastructure; D008563:Membrane Lipids / Q000378:metabolism*; D008854:Microscopy, Electron; D008928:Mitochondria / Q000378:metabolism* / Q000648:ultrastructure; D009491:Neurospora / Q000378:metabolism*; D009492:Neurospora crassa / Q000378:metabolism*
D003574:Cytochrome c Group; D008563:Membrane Lipids