Biorreatores de acetilcolinesterase: estudo de condições para a triagem de ligantes

Abstract

The development of ligand screening assays plays a very important role in the discovery of biologically active compounds. In this context, the use of immobilized capillary reactors has been adopted as a new technique for high throughput screening assays, which furnishes high selectivity, reproducibility. This work describes the covalent immobilization of electric fish (Electrophorus electricus) and human acetylcholinesterases (AChE) on fused silica capillaries and magnetic beads. The selected enzyme acts on the central nervous system and is a validated target for the treatment of Alzheimer s disease as for new insecticides. Zonal chromatography with the acetylcholinesterase capillary bioreactors was employed to determine kinetics constants, to a ligand screening assay of 79 compounds, and to inhibition mechanisms determination of the 05 identified ligands. A new approach to the screening of natural product extracts was developed based on ligand fishing experiments and zonal chromatography. For that, the magnetic beads were used for the ligand fishing experiments and capillary bioreactors for the activity assays. The later was employed also under nonlinear condition to determine the affinity constant of the fished ligand. This work reports also the identification by a solution assay of a new acetylcholinesterase substrate and, the studies by zonal bioaffinity chromatography to identify the bi-substrate mechanism.