Attenuation of p47(phox) and p67(phox) membrane translocation as the inhibitory mechanism of S-nitrosothiol on the respiratory burst oxidase in human neutrophils

The effect of the S-nitrosothiol (RSNO) on the activation of NADPH oxidase in human neutrophils was studied using an in vitro translocation system in which an anionic amphiphil, such as sodium dodecyl sulfate or arachidonate, plays a role as an activator. When membranes pretreated with RSNO and a cytosol fraction from resting neutrophils were combined to reconstitute the NADPH oxidase, both translocation of the cytosolic NADPH oxidase components such as p47(phox) and p67(phox) to thr plasma membrane fraction and subsequent superoxide generation was inhibited. However, RSNO had no effect on O-2(-) production when added after enzyme activation. A similar inhibition of translocation of recombinant p47(phox) was observed with RSNO-treated membrane. When the RSNO-treated membrane fraction was exposed to 2-mercaptoethanol the inhibition was reversed. The data suggest that RSNO inhibits translocation of p47(phox) Or p47(phox) containing cytosolic complex via a direct effect on the membrane component of the NADPH oxidase. (C) 1996 Academic Press, Inc.