Fusion of the mitochondrial outer membrane: use in forming large, two-dimensional crystals of the voltage-dependent, anion-selective channel protein.
Phospholipase A2 induces crystallization of the channel protein, VDAC (also called mitochondrial porin), in the outer membrane of Neurospora crassa mitochondria. The channel crystals formed in native membranes typically contain a few hundred unit cells. To increase the size of these membrane crystals for low-contrast electron microscopic imaging and diffraction studies, fusion of the isolated mitochondrial outer membranes was attempted before and after phospholipase treatment. Successful fusion of the untreated membranes was achieved by a procedure involving slow dehydration at acid pH. Single crystals of channels obtained by subsequent action of soluble phospholipase A2 on fused mitochondrial outer membranes may contain several thousand unit cells.
Mannella
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CA
Wadsworth Center for Laboratories and Research, New York State Department of Health, Albany 12201.
D003460:Crystallization; D004553:Electric Conductivity; D005656:Fungal Proteins / Q000502:physiology* / Q000648:ultrastructure; D007425:Intracellular Membranes / Q000502:physiology* / Q000648:ultrastructure; D007473:Ion Channels / Q000502:physiology*; D008561:Membrane Fusion / Q000187:drug effects; D008564:Membrane Potentials / Q000187:drug effects; D008928:Mitochondria / Q000502:physiology* / Q000648:ultrastructure; D009492:Neurospora crassa / Q000502:physiology; D010741:Phospholipases A; D054467:Phospholipases A2; D012995:Solubility
D005656:Fungal Proteins; D007473:Ion Channels; D010741:Phospholipases A; D054467:Phospholipases A2