Component of the alternative oxidase localized to the matrix surface of the inner membrane of plant mitochondria

FEBS Letters

Møller, Ian M.¹  Palmer, John M.²  Rasmusson, Allan G.¹ 

[1] Department of Plant Physiology, University of Lund, Box 7007, S-220 07 Lund, Sweden;Department of Pure and Applied Biology, Imperial College of Science, Technology and Medicine, Prince Consort Road, London SW7 2BB, England

关键词: Alternative pathway;    Inside-out submitochondrial particle;    Mitoplast;    Trypsin;    (Arum maculatum;    Plant;    Mitochondria);    BSA;    bovine serum albumin;    DQH2;    durohydroquinol;    m-Clam;    m-chlorobenzhydroxamic acid;    DCPIP;    2;    6-dichlorophenolindophenol;    FCCP carbonyl cyanide p-trifluoro-methoxyphenylhydrazone;    IO-SMP;    inside-out submitochondrial particles;    SDH;    succinate dehydrogenase;    SDS;    sodium dodecyl sulphate;   

DOI  :  10.1016/0014-5793(90)80034-G

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In mitoplasts from Arum maculatum spadices, succinate dehydrogenase (EC 1.3.99.1) and the alternative, cyanide-resistant oxidase activity (measured as m-chlorobenzhydroxamic acid-sensitive duroquinol oxidation) was unaffected by treatment with trypsin. In contrast, when 85% inside-out submitochondrial particles were treated with trypsin the alternative oxidase activity was inhibited by about 50% and succinate dehydrogenase activity by about 40%. Thus, a trypsin-sensitive component of the alternative pathway is located on the inner surface of the inner mitochondrial membrane. After trypsin treatment of the inside-out submitochondrial particles the inhibited alternative oxidase activity was partly restored by including 0.7 M citrate in the assay medium. This indicates that trypsin does not destroy the active site but merely causes a conformational change in the enzyme, thereby lowering its activity.

【 授权许可】

Unknown