Simultaneous presence of p47(phox) and flavocytochrome b-245 are required for the activation of NADPH oxidase by anionic amphiphiles. Evidence for an intermediate state of oxidase activation.
J Biol Chem
; 274(22): 15519-25, 1999 May 28.
Article
in En
| MEDLINE
| ID: mdl-10336445
ABSTRACT
We have examined the kinetics of NADPH oxidase activation induced by arachidonic acid or SDS in a cell-free system using mixtures of recombinant Phox proteins and purified flavocytochrome b-245. Activation of oxidase activity required the simultaneous presence of p47(phox), flavocytochrome b-245, and the anionic amphiphile. The activation of electron transfer reactions was much more rapid when iodonitrotetrazolium violet was used as electron acceptor than when oxygen alone was the acceptor. We propose that this difference represents an intermediate activation state of NADPH oxidase in which electron flow can proceed from NADPH to enzyme flavin (and hence to iodonitrotetrazolium violet) but not from flavin to heme (or not between the hemes). A model for NADPH oxidase activation is presented that is consistent with these observations.
Search on Google
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Phosphoproteins
/
Surface-Active Agents
/
NADPH Oxidases
/
Cytochrome b Group
Type of study:
Prognostic_studies
Language:
En
Journal:
J Biol Chem
Year:
1999
Document type:
Article
Affiliation country:
United States
Country of publication:
EEUU
/
ESTADOS UNIDOS
/
ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
/
US
/
USA