Rat liver mitochondria can hydrolyse thiamine pyrophosphate to thiamine monophosphate which can cross the mitochondrial membrane in a carrier‐mediated process

FEBS Letters

Passarella, Salvatore¹  Brizio, Carmen²  Quagliariello, Ernesto²  Valenti, Daniela²  Barile, Maria² 

[1] Dipartimento di Scienze Animali, Vegetali e dell'Ambiente, Università del Molise, Campobasso, Italy;Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, and Centro di Studio sui Mitocondri e Metabolismo Energetico, C.N.R., Via Orabona 4, 70126 Bari, Italy

关键词: Thiamine monophosphate;    Thiamine pyrophosphate;    Mitochondrial transport;    ADK;    adenylate kinase;    CAT;    carboxyatractyloside;    GDH;    glutamate dehydrogenase;    MAO;    monoamine oxidase;    pRLM;    purified rat liver mitochondria;    RLM;    rat liver mitochondria;    TMP;    thiamine monophosphate;    TPP;    thiamine pyrophosphate;    TPPase;    TPP pyrophoshatase;   

DOI  :  10.1016/S0014-5793(98)01007-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We show here that TPP→TMP conversion can take place in rat liver mitochondria. This occurs via the novel, putative TPP pyrophosphatase localised in the mitochondrial matrix, as shown both by digitonin titration and by an HPLC enzyme assay carried out on the mitochondrial matrix fraction. Certain features of the reaction, including the substrate and pH dependence, are reported. Additional evidence is given that externally added TMP can cross the mitochondrial membrane in a manner consistent with the occurrence of a carrier-mediated process. This can occur both via the TPP translocator and via a novel translocator, inhibited by CAT but different from the ADP/ATP carrier.

【 授权许可】

Unknown