Abstract 1804 Extending the Scope of a Coupled Assay to Measure Alanyl-Trna Synthetase Activity

Aminoacyl-tRNA synthetases are enzymes that catalyze the attachment of an amino acid to its corresponding tRNA, an essential step of protein synthesis. The most commonly used assay for monitoring aminoacylation catalyzed by alanyl-tRNA synthetase (AlaRS) utilizes radioactive alanine which allows for direct measurement of product formation, but is costly, time consuming, and requires sub-saturating concentrations of amino acid. We are interested in extending an assay developed for tyrosyl-tRNA synthetase1 that eliminates the need for radioactive amino acid by coupling the formation of AMP from the aminoacylation reaction to the reduction of NAD+ using two additional enzymes, AMP deaminase and IMP dehydrogenase.