Generation of Superoxide by purified and relipidated cytochrome b 559 in the absence of cytosolic activators

FEBS Letters

Pick, Edgar¹  Koshkin, Vasilij¹ 

[1] Laboratory of Immunopharmacology, Department of Human Microbiology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv 69978, Israel

关键词: Superoxide;    Cytochrome b559;    NADPH oxidase;    Phospholipid;    Phosphatidic acid;    FAD;    O2 −;    Superoxide;    SDS;    sodium dodecyl sulfate;    PAGE;    polyacrylamide gel electrophoresis;    EGTA;    [ethylenebis(oxyethylenenitrilo)]tetraacetic acid;    PMSF;    phenylmethylsulfonyl fluoride;    SOD;    Superoxide dismutase;    LDS;    lithium dodecyl sulfate;   

DOI  :  10.1016/0014-5793(93)81039-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Purified cytochrome b₅₅₉ from guinea pig macrophages was relipidated with several phospholipid mixtures. Relipidated cytochrome b₅₅₉ was found capable of NADPH-dependent Superoxide (O₂ ⁻) production in the absence of the cytosolic components of the NADPH oxidase complex. The rate of O₂ ⁻ generation by cytochrome b₅₅₉ varied with the type of phospholipid utilized for relipidation, was absolutely dependent on exogenous FAD, and was enhanced by a critical concentration of anionic amphiphile. It is demonstrated that exogenous FAD acts by binding to cytochrome b₅₅₉ . These results provide firm experimental evidence for the proposal that cytochrome b₅₅₉ comprises the complete electron transporting apparatus of the O₂ ⁻ forming NADPH oxidase and that the cytosolic components function merely as activators.

【 授权许可】

Unknown