Hussein_1999_Exp.Parasitol_91_144

Reference

Title : Nippostrongylus brasiliensis: characterisation of a somatic amphiphilic acetylcholinesterase with properties distinct from the secreted enzymes - Hussein_1999_Exp.Parasitol_91_144
Author(s) : Hussein AS , Grigg ME , Selkirk ME
Ref : Experimental Parasitology , 91 :144 , 1999
Abstract :

We have previously determined that Nippostrongylus brasiliensis secretes three monomeric nonamphiphilic (G1na) variants of acetylcholinesterase (AChE) with broadly similar properties. In this study we have examined AChE expression in somatic extracts of N. brasiliensis and report the identification of an additional enzyme which is not secreted. The enzyme was resolved by sucrose density gradient centrifugation with a sedimentation coefficient of 10.2 S which was shifted to 9.4 S in the presence of Triton X-100, identifying the enzyme as a tetrameric amphiphilic (G4a) form. The amphiphilic properties of this enzyme were confirmed by charge-shift electrophoresis, in which migration was accelerated by interaction with sodium deoxycholate. The enzyme showed low activity with butyrylthiocholine, and a Michaelis constant of 91 +/- 13 microM for acetylthiocholine was determined. It was highly sensitive to the AChE-specific inhibitor bis (4-allyldimethylammoniumphenyl)pentan-3-one dibromide, with an IC50 of 6.5 +/- 0.4 microM, but was also inhibited by the butyrylcholinesterase-specific inhibitor tetramonoisopropylpyrophosphortetramide, albeit with a higher IC50 of 46.5 +/- 6.1 microM. This enzyme can therefore be distinguished from the secreted AChEs by its amphiphilic properties, sedimentation in sucrose gradients, and sensitivity to cholinesterase inhibitors.

PubMedSearch : Hussein_1999_Exp.Parasitol_91_144
PubMedID: 9990342

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Citations formats

Hussein AS, Grigg ME, Selkirk ME (1999)
Nippostrongylus brasiliensis: characterisation of a somatic amphiphilic acetylcholinesterase with properties distinct from the secreted enzymes
Experimental Parasitology 91 :144

Hussein AS, Grigg ME, Selkirk ME (1999)
Experimental Parasitology 91 :144