Ligands for phosphatase binding assay

Abstract From the Canadian patent

Disclosed are new ligands for use in a binding assay for proteases and phosphatases, which contain cysteine in their binding sites or as a necessary structural component for enzymatic binding. The sulfhydryl group of cysteine is the nucleophilic group in the enzyme's mechanistic proteolytic and hydrolytic properties. The assay can be used to determine the ability of new unknown ligands and mixtures of compounds to competitively bind with the enzyme versus a known binding agent for the enzyme e.g. a known enzyme , inhibitor. By the use of a mutant form of the natural or native wild-type enzyme, in which serine, or another amino acid e.g. alanine, replaces , cysteine, the problem of …