ISSN:
1573-6881
Keywords:
Anion channel
;
anion uniport
;
transport in mitochondria
;
volume homeostasis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Physics
Notes:
Abstract The mitochondrial inner membrane possesses an anion channel (IMAC) which mediates the electrophoretic transport of a wide variety of anions and is believed to be an important component of the volume homeostatic mechanism. IMAC is regulated by matrix Mg2+ (IC50=38 µM at pH 7.4) and by matrix H+ (pIC50=7.7). Moreover, inhibition by Mg2+ is pH-dependent. IMAC is also reversibly inhibited by many cationic amphiphilic drugs, including propranolol, and irreversibly inhibited byN,N′-dicyclohexylcarbodiimide. Mercurials have two effects on its activity: (1) they increase the IC50 values for Mg2+, H+, and propranolol, and (2) they inhibit transport. The most potent inhibitor of IMAC is tributyltin, which blocks anion uniport in liver mitochondria at about 1 nmol/mg. The inhibitory dose is increased by mercurials; however, this effect appears to be unrelated to the other mercurial effects. IMAC also appears to be present in plant mitochondria; however, it is insensitive to inhibition by Mg2+, mercurials, andN,N′-dicyclohexylcarbodiimide. Some inhibitors of the adenine nucleotide translocase also inhibit IMAC, including Cibacron Blue, agaric acid, and palmitoyl CoA; however, atractyloside has no effect.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00769534
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