Long‐chain fatty acid‐promoted swelling of mitochondria: further evidence for the protonophoric effect of fatty acids in the inner mitochondrial membrane

FEBS Letters

Więckowski, Mariusz R.¹  Wojtczak, Lech¹  Schönfeld, Peter² 

[1] Nencki Institute of Experimental Biology, Warsaw, Poland;Institute of Biochemistry, Otto-von-Guericke University, Leipziger Str. 44, D-39120 Magdeburg, Germany

关键词: Fatty acid;    Protonophoric effect;    Anion carrier;    Uncoupling;    Swelling;    Mitochondrion;    BCECF;    2′;    7′-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein;    CAT;    carboxyatractyloside;    DCCD;    dicyclohexylcarbodiimide;    FFA;    non-esterified long-chain fatty acids;    FCCP;    carbonyl-cyanide p-trifluoromethoxyphenylhydrazone;    IMAC;    inner membrane anion carrier;    Val;    valinomycin;   

DOI  :  10.1016/S0014-5793(00)01376-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Swelling of non-respiring rat liver mitochondria suspended in isotonic potassium acetate at pH 6.5–7.4 in the presence of valinomycin was promoted by long-chain fatty acids, such as myristate, indicating a protonophoric mechanism. This swelling was partly inhibited by inhibitors or substrates of mitochondrial anion carriers. The results show that the fatty acid cycling mechanism responsible for uncoupling of oxidative phosphorylation can also operate in the direction opposite to that originally proposed [Skulachev, V.P. (1991) FEBS Lett. 294, 158–162], i.e. the inwardly directed transfer of the fatty acid anion accompanied by outwardly directed free passage of undissociated fatty acid. They also extend the list of mitochondrial anion carriers, that are involved in this process, over the mono- and tricarboxylate transporters. At pH 8, myristate, but not the synthetic protonophore, p-trifluoromethoxycarbonyl-cyanide phenylhydrazone, induced mitochondrial swelling in both potassium acetate and KCl media, that did not require the presence of valinomycin. This indicates that, at alkaline pH, myristate facilitates permeation of the inner mitochondrial membrane to monovalent cations and, possibly, activates the inner membrane anion channel.

【 授权许可】

Unknown