A variant X-linked chronic granulomatous disease patient (X91+) with partially functional cytochrome b.
Genetic analysis of a patient with the variant cytochrome b-245-positive form of chronic granulomatous disease revealed a missense mutation resulting in a Arg54-->Ser substitution in the gp91phox subunit of cytochrome b-245. As a consequence, although no O2- is made, NADPH oxidase-associated FAD accepts electrons from NADPH in the cell-free activation system and becomes reduced. The reduced flavin exhibits normal levels of iodonitrotetrazolium violet diaphorase activity, and the patient's neutrophils exhibit high levels of intracellular oxidant production and show a low level of NBT staining in the NBT slide test. Thus, this mutation appears to render the heme center of NADPH oxidase present but nonfunctional, while leaving the flavin center fully functional.
Cross
A R
AR
Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, California 92037, USA.
Heyworth
P G
PG
Rae
J
J
Curnutte
J T
JT
D000595:Amino Acid Sequence; D001692:Biological Transport; D002462:Cell Membrane / Q000201:enzymology; D003573:Cytochrome b Group / Q000378:metabolism*; D008058:Dihydrolipoamide Dehydrogenase / Q000378:metabolism; D008040:Genetic Linkage; D006105:Granulomatous Disease, Chronic / Q000201:enzymology / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D009154:Mutation; D009252:NADPH Dehydrogenase / Q000378:metabolism; D019255:NADPH Oxidases; D009504:Neutrophils / Q000201:enzymology; D010750:Phosphoproteins / Q000378:metabolism; D013057:Spectrum Analysis; D014960:X Chromosome
D003573:Cytochrome b Group; D010750:Phosphoproteins; C079789:neutrophil cytosol factor 67K; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1; D009252:NADPH Dehydrogenase; D008058:Dihydrolipoamide Dehydrogenase