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The mitochondrial uncoupling protein from guinea-pig brown adipose tissue. Synchronous increase in structural and functional parameters during cold-adaptation.

ABSTRACT: The time-course for the induction of the uncoupling pathway in the inner membrane of brown-fat mitochondria from cold-adapting guinea pigs was studied. The amount of the protein was quantified from the capacity for high-affinity binding of GDP to the intact mitochondria, and was compared with the functional parameters diagnostic of the protein, namely the nucleotide-sensitive proton conductance and the sensitivity to uncoupling by low concentrations of fatty acids. A monophasic increase in nucleotide titre was observed, with no evidence of an early 'unmasking' of preexisting nucleotide-binding sites. The nucleotide-sensitive conductance increased in precise synchrony with the nucleotide-binding capacity. Mitochondria from newborn animals, and those from acutely cold-adapted animals, showed anomalously low sensitivities to uncoupling by fatty acids.

SUBMITTER: Rial E

PROVIDER: S-EPMC1144231 | biostudies-other | 1984 Sep

REPOSITORIES: biostudies-other

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