Methoxatin (PQQ) in guinea-pig neutrophils.
PQQ, also called methoxatin, has been isolated from guinea-pig neutrophils. The organic cations diphenyleneiodonium (DPI) and diphenyliodonium (BPI) and the aromatic o-diamine 4,5-dimethylphenylenediamine (DIMPDA) sequester synthetic PQQ and inhibit its redox-cycling activity in a model system. Standards were made of adducts of tritiated PQQ with unlabeled DIMPDA and of unlabeled PQQ with tritiated DPI or DIMPDA. PQQ adducts were isolated from guinea-pig neutrophils with each of the tritiated inhibitors. They were separated and defined by high-performance liquid chromatography (HPLC). Tiron, a disodium benzene disulphonic acid, broke the DPI-PQQ adduct isolated from neutrophils and released free PQQ. Both DPI and DIMPDA, as well as BPI, blocked O2.- release by stimulated neutrophils. The blockade exerted by these inhibitors was released by the addition of PQQ to the cell suspensions. The data demonstrate the presence of PQQ in guinea-pig neutrophils and suggest that it has a possible role, direct or indirect, in the O2.(-)-producing respiratory burst.
Bishop
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A
Department of Genetics, Harvard Medical School, Harvard School of Dental Medicine, Boston, MA.
Paz
M A
MA
Gallop
P M
PM
Karnovsky
M L
ML
D000818:Animals; D001713:Biphenyl Compounds; D002851:Chromatography, High Pressure Liquid; D003067:Coenzymes / Q000097:blood; D006168:Guinea Pigs; D066298:In Vitro Techniques; D009504:Neutrophils / Q000737:chemistry* / Q000187:drug effects / Q000502:physiology; D009861:Onium Compounds; D045542:PQQ Cofactor; D010655:Phenylenediamines; D015363:Quinolones / Q000097:blood* / Q000302:isolation & purification; D016897:Respiratory Burst; D013481:Superoxides / Q000097:blood; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014316:Tritium
D001713:Biphenyl Compounds; D003067:Coenzymes; D009861:Onium Compounds; D010655:Phenylenediamines; D015363:Quinolones; D014316:Tritium; C031291:diphenyliodonium; D013481:Superoxides; C011793:4,5-dimethyl-1,2-phenylenediamine; C007517:diphenyleneiodonium; D045542:PQQ Cofactor; D013755:Tetradecanoylphorbol Acetate