A COMPARATIVE STUDY OF VERTEBRATE ESTERASE MULTIPLICITY

1. 1. The properties of the multiple enzyme forms of soluble esterase activity have been studied in three non-mammalian species-lizard, frog and catfish. 2. 2. The resultant data has enabled a review and classification of esterase heterogeneity over a representative range of vertebrate phylogeny. 3. 3. Four main classes of esterase activity have been characterized (carboxyl-esterases, arylesterases, acetylesterases and cholinesterases), but evidence for further differentiation of activity-types within these groups is also presented. 4. 4. Considerable molecular variation is evident between species and a late evolutionary development of some esterase types (e.g. acetylesterases, group I carboxylesterases and cholinesterases) seems indicated. © 1968.