Identification of neutrophil NADPH oxidase proteins gp91-phox, p22-phox, p67-phox, and p47-phox in mammalian species.

OBJECTIVE

To identify and characterize 4 components of the NADPH oxidase complex, gp91-phox, p22-phox, p67-phox, and p47-phox, in common laboratory animal species.

ANIMALS

2 clinically normal animals from each of the following species: rabbit, sheep, cow, pig, and macaque (Macaca nemistrina). A pool of 8 rats.

PROCEDURE

Neutrophils were harvested from blood, Membrane and cytosol fractions were isolated and separated by sodium dodecyl sulfate-polyacrylamide gels. Gels were transferred, and immunoblots were probed with antibodies directed against individual human NADPH oxidase proteins. Human neutrophil membrane and cytosol fractions served as controls.

RESULTS

Immunoreactive bands were observed in all species for gp91-phox, p67-phox, and p47-phox proteins. Immunoreactive bands for p22-phox protein were observed in cells from rats, rabbits, pigs, and macaques.

CONCLUSIONS

The NADPH oxidase and its component proteins have been highly conserved across mammalian species. Lack of immunoreactivity to p22-phox in sheep and cows can be explained by sequence divergence and epitope variability at the p22-phox C-terminus.

CLINICAL RELEVANCE

The high degree of NADPH oxidase protein conservation may allow the existing knowledge of the human neutrophil NADPH oxidase to be applied to the study of animal disease.