PURIFICATION AND CHARACTERIZATION OF ACETYLCHOLINESTERASE FROM DESERTCOBRA (WALTERINNESIA-AEGYPTIA) VENOM

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. A ChE was purified to homogeneity as established by sodium dodecylsulfat e/polyacrylamide gel electrophoresis. The specific activity of AChE wa s 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 r evealed that the enzyme exists in different isoforms, with isoelectric points ranging between pH 7.4-7.9. The kinetic parameters (K-m and V- max) and IC50 of AChE inhibition by procaine, tetracaine and physostig mine were investigated in the present study.