● Directed Evolution allows developments of therapeutic proteins and industrial enzymes.

● ; unmodified therapeutic proteins are unstable and have immunogenicity. 
● Poly ethylene glycol (PEG) modification circumvents the above problems ;  modification at a random site decreases  protein activity.
● Although protein mutants without Lysine residue can be site-specifically modified, design of such mutants is difficult.
● ; directed evolution often shows incomplete increase in properties of such proteins.

● Our directed evolution creates a protein which  has only one modification site.
● The key for the above evolution is our “simplified genetic codes” which do not  encode Lysine.
● Our ”moving average genetic code” keeps increasing of a desired property of proteins  during directed evolution. 

● Site-specific modification of proteins by using conventional reagents.
● Taking full advantage of increase of protein activity by directed evolution.
● Creation of protein mutants which can not be obtained by the other methods.
● Large scale production with conventional culture and purification procedure is available for any mutant proteins evolved with our engineered genetic code.

● Therapeutic proteins.
● Enzymes used in oxidized conditions (ex. washing detergent).
● Proteins used in industries.