Methylation is a ubiquitous covalent modification used to control the function of diverse biomolecules including hormones, neurotransmitters, xenobiotics, proteins, nucleic acids and lipids. Histone methyltransferases (HMTs) are currently of high interest as drug targets because of their role in epigenetic regulation, however most HMT assay methods are either not amenable to an HTS environment or are applicable to a limited number of enzymes. We developed a generic methyltransferase assay method using fluorescent immunodetection of AMP, which is formed from the MT reaction product S-adenosylhomocysteine in a dual enzyme coupling step. The detection range of the assay, its suitability for HTS, including stability of reagents following dispensing and after addition to reactions as well as the potential for interference from drug like molecules was investigated. In addition, the use of the assay for measuring inhibitor potencies with peptide or intact protein substrates was examined through pilot screening with selected reference enzymes including HMT G9a. By combining a novel enzymatic coupling step with the well characterized Transcreener® AMP/GMP assay, we have developed a robust HTS assay for HMTs which should be broadly applicable to other types of methyltransferases as well.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.