Interactions between NADPH oxidase and voltage‐gated proton channels: why electron transport depends on proton transport

FEBS Letters

DeCoursey, Thomas E¹ 

[1] Department of Molecular Biophysics and Physiology, Rush Presbyterian St. Luke's Medical Center, 1750 West Harrison, Chicago, IL 60612, USA

关键词: Phagocyte;    Respiratory burst;    Ion channel;    Membrane potential;    Superoxide;    pH;    FAD;    flavin adenine dinucleotide;    I e;    electron current;    NADPH;    nicotinamide adenine dinucleotide phosphate;    V;    voltage;    V threshold;    the threshold voltage for activation of voltage-gated proton channels;   

DOI  :  10.1016/S0014-5793(03)01103-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Leukocytes kill microbes by producing reactive oxygen species, using a multi-component enzyme complex, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Electrons pass from intracellular NADPH through a redox chain within the enzyme, to reduce extracellular O₂ to O₂ ⁻. Electron flux is electrogenic, and rapidly depolarizes the membrane potential. Excessive depolarization can turn off electron transport by self-inhibition, but this is prevented by proton flux that balances the electron flux. Although the membrane potential depolarizes by ∼100 mV during the respiratory burst (NADPH oxidase activity), NADPH oxidase activity is independent of voltage in this range, which permits optimal function and prevents self-inhibition.

【 授权许可】

Unknown