Solubilization of neuropathy target esterase and other phenyl valerate carboxylesterases from chicken embryonic brain by phospholipase A2.
Membrane-bound neuropathy target esterase (NTE) and associated phenyl valerate carboxylesterases were solubilized from chicken embryo brain by phospholipase A2. Phospholipase A2 from bee or cobra (Naja) venoms were the most effective preparations in solubilizing brain NTE and other phenyl valerate carboxylesterases. Phospholipase C and several proteinases (endoproteinase, pronase E, proteinase K, thermolysin, trypsin) did not solubilize brain membrane-bound carboxylesterases but reduced their activity. NTE solubilization by phospholipase A2 did not affect its apparent Km and Vmax for the substrate phenyl valerate or the susceptibility of phenyl valerate carboxylesterases to inhibition by paraoxon and mipafox. NTE thermal stability diminished after the treatment of brain membrane fragments with phospholipase A2.
Seifert
J
J
Department of Avian Sciences, University of California, Davis 95616.
Wilson
B W
BW
D000818:Animals; D001514:Bee Venoms / Q000201:enzymology; D001921:Brain / Q000196:embryology / Q000201:enzymology*; D002265:Carboxylic Ester Hydrolases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002642:Chick Embryo; D004795:Enzyme Stability; D006358:Hot Temperature; D007531:Isoflurophate / Q000031:analogs & derivatives / Q000494:pharmacology; D010261:Paraoxon / Q000494:pharmacology; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D012910:Snake Venoms / Q000201:enzymology; D013379:Substrate Specificity
D001514:Bee Venoms; D012910:Snake Venoms; D007531:Isoflurophate; C005238:mipafox; D002265:Carboxylic Ester Hydrolases; C021859:neurotoxic esterase; D010741:Phospholipases A; D054467:Phospholipases A2; D010261:Paraoxon