title: GTP-dependent and -independent activation of superoxide producing NADPH oxidase in a neutrophil cell-free system.
abstract: GTP and GTP-gamma-S enhanced several-fold the NADPH-dependent superoxide production induced by sodium dodecyl sulfate in a cell-free system of pig neutrophils consisting of the membrane fraction and two cytosolic fractions separated by gel filtration. The enhanced activity was decreased by the addition of GDP in a dose-dependent manner, but 70% of the activity in the absence of GTP remained even at 1 mM GDP. Only one cytosol fraction besides the membrane fraction was required for the activation in the presence of GTP. The cytosol fraction was analyzed by chromatography on 2',5'-ADP agarose and two components responsible for the GTP-dependent and independent activation were separated. These results suggest that at least two pathways are available for the activation of superoxide production in the cell-free system of pig neutrophils.
authors.affiliation: Department of Biochemistry, Kyushu University School of Medicine, Fukuoka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ishida
authors.forename: K
authors.initials: K
authors.lastname: Takeshige
authors.forename: S
authors.initials: S
authors.lastname: Takasugi
authors.forename: S
authors.initials: S
authors.lastname: Minakami
mesh_terms: D000818:Animals; D002474:Cell-Free System; D002850:Chromatography, Gel; D003600:Cytosol / Q000378:metabolism; D004789:Enzyme Activation; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology*; D066298:In Vitro Techniques; D009247:NADH, NADPH Oxidoreductases / Q000097:blood*; D019255:NADPH Oxidases; D009504:Neutrophils / Q000378:metabolism*; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D013481:Superoxides / Q000097:blood*; D013552:Swine; D013873:Thionucleotides / Q000494:pharmacology
chemical_list: D013873:Thionucleotides; D013481:Superoxides; D012967:Sodium Dodecyl Sulfate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases