PROCESS FOR DETECTING ENZYME ACTIVITY IN AN IMMUNOASSAY

摘要

Detection of hydrolytic enzyme activity in an immunoassay comprises incubating a dually modified luminescent labelled protein/peptide, comprising a first modified position as a substrate for an enzyme and a second modified position as an affinity enhancer for an antibody, and adding an antibody discriminating the dually modified substrate from the enzyme generated product. The method is useful for detecting enzyme activity in an immunoassay of phosphatases PP2A and PP1 using TAMRA-Iabelled bisphosphorylated peptides, and of Histone H3 acetylase or deacetylase activity using TAMRA-labelled bisacetylated-monophosphorylated peptides. In addition the method is useful for screening modulators for enzyme activity. For the histone H3 (de)acetylase assay a bisacetylated labelled peptide can only be sufficiently discriminated by an antibody from the monoacetylated substrate if a third modified residue i.e. a phosphorylated residue is present in the peptide as affinity enhancer.