Startseite Lebenswissenschaften Human butyrylcholinesterase components differ in aryl acylamidase activity
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Human butyrylcholinesterase components differ in aryl acylamidase activity

  • María F. Montenegro , María T. Moral-Naranjo , María Páez de la Cadena , Francisco J. Campoy , Encarnación Muñoz-Delgado und Cecilio J. Vidal
Veröffentlicht/Copyright: 27. März 2008
Biological Chemistry
Aus der Zeitschrift Band 389 Heft 4

Abstract

Apart from its esterase activity, butyrylcholinesterase (BuChE) displays aryl acylamidase (AAA) activity able to hydrolyze o-nitroacetanilide (ONA) and its trifluoro-derivative (F-ONA). We report here that, despite amidase and esterase sites residing in the same protein, in human samples depleted of acetylcholinesterase the ratio of amidase to esterase activity varied depending on the source of BuChE. The much faster degradation of ONA and F-ONA by BuChE monomers (G1) of colon and kidney than by the tetramers (G4) suggests aggregation-driven differences in the AAA site between single and polymerized subunits. The similar ratio of F-ONA to butyrylthiocholine hydrolysis by serum G1 and G4 forms support structural differences in the amidase site according to the source of BuChE. The changing ratios of amidase to esterase activities in the human sources probably arise from post-translational modifications in BuChE subunits, the specific proportion of monomers and oligomers and the variable capacity of the tetramers for degrading ONA and F-ONA. The elevated amidase activity of BuChE monomers and the scant activity of the tetramers justify the occurrence of single BuChE subunits in cells as a means to sustain the AAA activity of BuChE which otherwise could be lost by tetramerization.


Corresponding author

Received: 2007-11-2
Accepted: 2007-12-17
Published Online: 2008-03-27
Published in Print: 2008-04-01

©2008 by Walter de Gruyter Berlin New York

Heruntergeladen am 19.12.2025 von https://www.degruyterbrill.com/document/doi/10.1515/BC.2008.041/pdf
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