Comprehensive step-by-step engineering of an (R)-hydroxynitrile lyase for large-scale asymmetric synthesis

A custom-made enzyme: The gene and protein sequence of a new (R)-hydroxynitrile lyase from Prunus amygdalus was cloned and engineered for recombinant production on a large scale. The enzyme is stable and active at low pH values. A rationally designed active-site mutant now permits the rapid and stereoselective synthesis of sterically hindered cyanohydrins such as ortho-chloromandelonitrile (see picture).