The '
NADPH oxidase' (nicotinamide adenine dinucleotide phosphate-oxidase) complex is an
enzyme complex
Subunits
It is made up of six subunits. These subunits are:
★ a
Rho guanosine triphosphatase (
GTPase), usually Rac1 or Rac2 (Rac stands for Rho-related C3
botulinum toxin substrate)
★ Five "phox" units. (''Phox'' stands for
phagocytic oxidase.)
★ gp91''phox''
★ p22''phox''
★ p40''phox''
★ p47''phox''
★ p67''phox''
Function
The complex is normally latent in
neutrophils and is activated to assemble in the membranes during
respiratory burst.
It generates
superoxide by transferring
electrons from
NADPH inside the cell across the
membrane and coupling these to molecular
oxygen to produce the superoxide, which is highly reactive free radical. Superoxide can be produced into phagosomes which contain ingested
bacteria and
fungi, or it can be produced outside of the cell.
Superoxide is capable of killing
bacteria and fungi by its ability to react with other body compounds to generate a large family of reactive oxygen species. These include
hydrogen peroxide and
hypochlorous acid, the reactive agent in
bleach.
Inihibition
NADPH oxidase can be inhibited by
apocynin and DPI.Apocynin prevents the assembly of its subunits.
External links
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