ISSN:
1573-6881
Keywords:
Electrophysiology
;
peptide-sensitive channel
;
mitochondrial megachannel
;
porin
;
planar bilayer
;
yeast mitochondria
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Physics
Notes:
Abstract The high-conductance channels present in the outer membranes of wild-type and porin-less yeast mitochondria have been characterized electrophysiologically after incorporation in planar bilayer membranes. The most prominent activity was ascribed to a voltage-dependent, substaterich, cationic channel which generally inactivated at potentials positive in thecis compartment, in agreement with the observations from patch-clamp experiments on porin-less mitoplasts. This channel has been identified as the so-called “peptide-sensitive channel” (PSC). We also observed similar channels displaying either no inactivation, or inactivation at both positive and negative potentials. These latter properties match those already described for mammalian and yeast PSC, respectively. These different behaviors are tentatively explained as arising from the presence, or lack of, peptides bound to the PSC. Very high conductances, apparently due to cooperative gating, were frequently displayed. In wild-type membranes, activity ascribable to the porin was also observed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02110650
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