Methyltransferase-Glo: a universal, bioluminescent and homogenous assay for monitoring all classes of methyltransferases

Aim: To develop a homogenous, nonradioactive, antibody-free and universal assay for diverse families of methyltransferases and monitor the activity of these enzymes in a high-throughput format. Materials & methods: The assay conditions are optimized for monitoring the enzymatic activity of a broad range of methyltransferases regardless of the chemical structure or nature of the enzyme substrate in a low- and high-throughput-formatted protocols. The assay detects S-adenosyl-l-homocysteine, the universal reaction products of all methyltransferases. Results: We demonstrate the utility of using this protocol to determine the activity of DNA, protein methyltransferases and also to determine kinetic parameters of several inhibitors using purified enzymes. The assay is sensitive (20–30 nM of S-adenosyl-l-homocysteine) and robust. Conclusion: The methyltransferase Glo is nonradioactive, antibody-free and homogenous, universal assay to determine enzyme activity of diverse families of methyltransferases. The assay is formatted to meet the requirements of high-throughput screening in drug discovery programs searching for modulators of methyltransferases.