TABLE 2.
O2−-generating ability of flavocytochrome b558 treated with GT in vitro
| Medium conditions | NADPH oxidase activitya
|
|
|---|---|---|
| Mean amt (mol/s/mol of heme) ± SD | Mean % inhibition ± SD | |
| −GT | 26.6 ± 0.3 | 0.0 ± 1.1 |
| +GT | 4.6 ± 0.6 | 82.7 ± 2.3 |
a
Membranes from untreated neutrophils were treated in vitro with GT (2 nmol of GT/pmol of heme; see the legend for Fig. 6) and washed by centrifugation. One picomole of heme equivalent of flavocytochrome b558 was then combined with recombinant cytosolic components (252 pmol of rp47phox, 36 pmol of rp67phox, and 252 pmol of GTPγS-loaded Rac2) for the reconstitution of NADPH oxidase activity in a cell-free assay (see Materials and Methods). O2− generation was determined by the cytochrome c assay. Data show the means of two experiments done in duplicate.