Incorporation in lipid bilayers of a large conductance cationic channel from mitochondrial membranes.
AUTOR(ES)
Thieffry, M
RESUMO
Membranes from subcellular fractions of adrenal medulla were incorporated in phospholipid bilayers formed at the tip of microelectrodes. Current fluctuations recorded in the presence of a transmembrane potential revealed the existence of a voltage-dependent channel of large conductance. This channel is characterized by fast kinetics and four conductance levels separated by jumps of 100, 220 and 220 pS in 150 mM NaCl. It is permeant to Na+,K+, tetraethylammonium, Cl- and acetate and has some cation selectivity. Exposure to trypsin or pronase abolished the voltage-dependence. Upon subcellular fractionation, the activity was found to be associated with mitochondria. A similar activity was observed in mitochondrial fractions from other organs. By its kinetics, its selectivity and its potential-dependence, this channel differs from the voltage-dependent anion channel of outer mitochondrial membranes.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=458395Documentos Relacionados
- Extracellular ATP induces a large nonselective conductance in macrophage plasma membranes.
- Cloning and in situ localization of a brain-derived porin that constitutes a large-conductance anion channel in astrocytic plasma membranes.
- ATP-Sensitive Anion Channel from Rat Brain Synaptosomal Membranes Incorporated into Planar Lipid Bilayers
- Reconstitution in planar lipid bilayers of a Ca2+-dependent K+ channel from transverse tubule membranes isolated from rabbit skeletal muscle.
- Purification and Characterization of the Voltage-Dependent Anion-Selective Channel Protein from Wheat Mitochondrial Membranes.