p67-phox enhances the binding of p47-phox to the human neutrophil respiratory burst oxidase complex.

Assembly of phagocyte NADPH oxidase: A concerted binding process?

“…Therefore, in these experimental conditions the activation of cytosolic proteins is not a limiting factor of the assembly process. Our results are in agreement with the hypothesis of separate binding sites for p47 phox and p67 phox on the cytochrome [1,28,31]. Indeed: i) in the absence of p47 phox , p67 phox is able to participate to an active complex (this paper and [30,32]; ii) deletion of the C-terminal region of p47 phox , which is involved in the p47 phox -p67 phox complex does not prevent the binding of p67 phox to cyt b558; iii) the determined EC50 values are different for each cytosolic proteins.…”

“…As shown in this paper, the incubation period is critical. Different protocols that affect the EC50 values are currently used: mixing of very concentrated proteins solutions, followed by dilution [19,28]; the use of purified and relipidated cytochrome b558 [19,29,30]. For example, if the complex does not dissociate after dilution, the EC50 should be calculated from the concentration used during the incubation period and not during the activity measurement.…”

On the Mechanism of Inhibition of the Neutrophil Respiratory Burst Oxidase by a Peptide from the C-Terminus of the Large Subunit of Cytochrome b558

“…phox and p67-phox with the oxidase complex is a mutually facilitated process, with the binding of either protein affecting the binding of the other (Uhlinger et al, 1994).…”