Transmembrane electron transport in ascorbate‐loaded plasma membrane vesicles from higher plants involves a b‐type cytochrome

FEBS Letters

Horemans, N.¹  Asard, H.¹  Caubergs, R.J.¹ 

[1] Department of Biology, University of Antwerp (RUCA), Groenenborgerlaan 171, B-2020 Antwerp, Belgium

关键词: Plasma membrane;    Electron transport;    Ascorbic acid;    Cytochrome b;    Phaseolus vulgaris L;    E′0;    redox potential at pH 7.0;    EDTA;    ethylenediaminetetraacetic acid;    HEPES;    N-(2-hydroxyethyl)piperazine-N′-2-ethanesulfonic acid;    PEG;    poly(ethylene glycol);   

DOI  :  10.1016/0014-5793(92)80986-Q

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The possible involvement of a high-potential b-type cytochrome in plasma membrane electron transport was tested using ascorbate-loaded membrane vesicles. Absorption spectra demonstrated that the cytochrome was about 89% reduced in these preparations. Use of ascorbate oxidase and washing of the vesicles further indicated flat reduction was mediated by intra-vesicular ascorbate. Addition of low concentrations of ferricyanide caused a rapid cytochrome oxidation followed by a slower re-reduction. The Kinetics of this response indicate that the electron acceptor was fully reduced berore re-reduction of the cytochrome occurred. These observations suggest that the b-type cytochrome mediates transmembrane electron transfer.

【 授权许可】

Unknown