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RECORD NUMBER: 4 OF 11

OLS Field Name OLS Field Data
Main Title Direct Method to Assay Neurotoxic Esterase Activity.
Author Soliman, Salah A. ; Curley, August ; El-Sebae, Abdel-Khalek ;
CORP Author Health Effects Research Lab., Research Triangle Park, NC.
Year Published 1980
Report Number EPA-68-02-3252; EPA-600/J-81-510;
Stock Number PB82-154766
Additional Subjects Esterases ; Photometry ; Reaction kinetics ; Assaying ; Chickens ; Brains ; Activity ; Substrates ; Reprints ; Valeric acid/(nitrophenyl-ester) ; Neurotoxins ; Caproic acid/(nitrophenyl-ester)
Holdings
Library Call Number Additional Info Location Last
Modified
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Status
NTIS  PB82-154766 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 06/23/1988
Collation 8p
Abstract
A direct photometric method for assaying neurotoxic esterase (NTE) activity of chicken brain microsomal preparation has been developed using 4-nitrophenyl esters as substrates. Paired samples of the microsomal preparation were preincubated for 20 min. with paraoxon plus either (a) buffer or (b) mipafox before addition of substrate. The initial rate of NTE activity was directly recorded at 410 nm by matching the content of tube (a) against tube (b) after addition of the substrate to both of them. The 4-nitrophenyl esters of propionic, butyric, valeric, lauric, capric and caproic acids were tested as substrates. Results indicated that 4-nitrophenyl valerate and caporate, respectively, are the most hydrolyzable substrates for NTE with this method; it also enables detained kinetic studies of NTE to be made. The Michaelis constant (Km) for the hydrolysis of 4-nitrophenyl valerate by NTE was found to be 0.0000555M.