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PubMed · 7115697

K+ transport in mitoplasts.

H S Chang·J J Diwan
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Abstract

K+ transport into mitoplasts, prepared by digitonin disruption and removal of the outer membranes from rat liver mitochondria, has been studied. Unidirectional K+ influx has been measured by means of 42K, in the presence of the respiratory substrate succinate. K+ influx is inhibited by CN-, antimycin A and dicyclohexylcarbodiimide, but is insensitive to oligomycin. A linear dependence of the reciprocal of the K+ -influx rate on the reciprocal of the external K+ concentration is observed. Under the conditions studied, the apparent Km for K+ of the transport mechanism is approx. 6 mM, while the Vmax of K+ influx is approx. 5 mu mol K+/g protein per min. The rate of K+ influx increases with increasing external pH over the range from 6.8 to 8.0. The observed kinetics, pH dependence and inhibitor sensitivity are essentially similar to previously reported characteristics of K+ transport into intact rat liver mitochondria. It is concluded that the outer mitochondrial membrane does not not have a role in controlling K+ flux into rat liver mitochondria.

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Adenosine DiphosphateAnimalsBiological Transport, ActiveCyanidesKineticsMitochondria, LiverOxygen ConsumptionPotassiumRatsJournal ArticleResearch Support, U.S. Gov't, P.H.S.

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H S Chang, J J Diwan. 1982-08-20. K+ transport in mitoplasts.. https://doi.org/10.1016/0005-2728(82)90025-1

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