Comparison of recombinant wild-type Fas expressed in E.coli to native Fas purified from mamba venom. Activity profiles of TcAChE when inhibited by recombinant wild-type Fas (closed triangle) and by native Fas (closed circle). [Fas] are plotted on a log scale. TcAChE activity is measured with an accuracy of ±0.05. An insert shows an SDS–PAGE gel for equal amounts of recombinant Fas (lane 1) and native Fas (lane 2). Molecular weight markers are shown in the leftmost lane.