title: Purification and characterization of acetylcholinesterase from desert cobra (Walterinnesia aegyptia) venom.
abstract: Acetylcholinesterase (AChE) has been identified and purified from the venom of desert cobra (W aegyptia) to apparent homogeneity using a TSK G 3000 SW gel filtration column and a Mono Q anion-exchange column. AChE was purified to homogeneity as established by sodium dodecylsulfate/polyacrylamide gel electrophoresis. The specific activity of AChE was 357 IU/mg with acetylthiocholine iodide as substrate. The denatured W aegyptia venom AChE displayed a molecular mass of 67000 +/- 3000 Da suggesting it was a single polypeptide. Isoelectric focusing of AChE revealed that the enzyme exists in different isoforms, with isoelectric points ranging between pH 7.4-7.9. The kinetic parameters (Km and Vmax) and IC50 of AChE inhibition by procaine, tetracaine and physostigmine were investigated in the present study.
authors.affiliation: Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia.
authors.forename: A S
authors.initials: AS
authors.lastname: Duhaiman
authors.forename: A S
authors.initials: AS
authors.lastname: Alhomida
authors.forename: N
authors.initials: N
authors.lastname: Rabbani
authors.forename: M A
authors.initials: MA
authors.lastname: Kamal
authors.forename: A A
authors.initials: AA
authors.lastname: al-Jafari
mesh_terms: D000110:Acetylcholinesterase / Q000737:chemistry / Q000187:drug effects / Q000302:isolation & purification* / Q000378:metabolism; D000818:Animals; D002800:Cholinesterase Inhibitors / Q000494:pharmacology; D004546:Elapid Venoms / Q000201:enzymology*; D017815:Elapidae
chemical_list: D002800:Cholinesterase Inhibitors; D004546:Elapid Venoms; D000110:Acetylcholinesterase