A novel multi-enzymatic high throughput assay for transaminase activity

Aminotransferases (ATs) are crucial enzymes for prokaryote and eukaryote metabolism, and have attracted industrial attention for large scale synthesis of amino acids and chiral amines. A high throughput screening procedure for branched chain aminotransferases (BCATs) was developed to identify optimal expression on a large number of expression clones. Escherichia coli BCAT, encoded by the ilvE gene, was expressed in E. coli and Pichia pastoris. This simple colorimetric assay procedure allowed the identification of optimal clones for ilvE expression and enabled the testing of its activity in cell lysates or on whole cell catalysis.