Initial characterization of the organophosphate acid anhydrase activity of the chicken, Gallus domesticus.
1. Supernatant solutions from kidney and liver homogenates of the chicken, Gallus domesticus, were found to hydrolyze the organophosphate (OP) compound diisopropylfluorophosphate (DFP). The activity on DFP as substrate was heat-inactivated and was characterized for temperature and pH optima, enzyme kinetics, and requirements for manganous ion. 2. Gel column chromatography indicated that the DFPase in both tissues is in the range of 82,100 to 93,300 D. This activity is strongly inhibited by N,N'-diisopropylphosphorodia-midofluoridate (mipafox). 3. The chicken has organophosphate acid (OPA) anhydrase activity comparable to other eucaryotic sources in its ability to hydrolyze DFP. Although birds may not have paraoxonase activity comparable to mammalian species, they do not differ significantly in the ability to hydrolyze DFP and probably related compounds.
Institute of Environmental Toxicology and Chemistry, Huxley College of Environmental Studies, Western Washington University, Bellingham 98225.
B D
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Westra
W G
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Landis
D000818:Animals; D043303:Aryldialkylphosphatase; D002645:Chickens; D002712:Chlorides; D002850:Chromatography, Gel; D004492:Edetic Acid / Q000494:pharmacology; D005260:Female; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007668:Kidney / Q000187:drug effects / Q000201:enzymology; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D008297:Male; D008345:Manganese / Q000494:pharmacology; D017895:Manganese Compounds; D010744:Phosphoric Monoester Hydrolases / Q000037:antagonists & inhibitors / Q000737:chemistry*; D011489:Protein Denaturation; D013347:Subcellular Fractions / Q000187:drug effects / Q000201:enzymology; D013696:Temperature
D002712:Chlorides; D017895:Manganese Compounds; D008345:Manganese; D004492:Edetic Acid; D010744:Phosphoric Monoester Hydrolases; D043303:Aryldialkylphosphatase; C025340:manganese chloride