Using a new approach to engineer enzyme activity——semi-rational design

Many research groups successfully rely on whole-gene random mutagenesis and recombination approaches for the directed evolution of enzymes.Recent advances in enzyme engineering have used a combination of these random methods of directed evolution with elements of rational enzyme modification to successfully by-pass certain limitations of both directed evolution and rational design.Semi-rational approaches that target multiple,specific residues to mutate on the basis of prior structural or functional knowledge create 'smart' libraries that are more likely to yield positive results.Efficient sampling of mutations likely to affect enzyme function has been conducted to both experiment and on a much greater scale,computation,with remarkable improvements in substrate selectivity and specificity and in the redesign of enzyme activities within known structure.