An analysis of esterase activities from surgeonfish tissues yields evidence of an atypical pseudocholinesterase

1. Esterases from tissues of the surgeonfish (Teleostei, Perciformes, Acanthuridae) are characterized electrophoretically and include several carboxylesterases, an acetylesterase, and an atypical pseudocholinesterase (pseudo-ChE). 2. The pseudo-ChE occurs in several isozymic forms including sialated and asialated slightly-anodal forms found principally in liver, and a larger, asialated asymmetric form that barely penetrates the 10% PAGE gel matrix found together with true AChE in epaxial muscle, brain, and eye. 3. Characterization of these three pseudo-ChE activities suggest that they are decidedly atypical in the intermediacy of their substrate and inhibitor specificities relative to classically-defined AChE and pseudo-ChE activities.