Figure 2.

The construction of recombinant proteins can be done using three different approaches. Rational design is used to modify a specific amino acid that is known to be related to characteristics that need to be changed. If no information is known about the enzyme’s structure and mechanism, both directed evolution and semi-rational design can be used. For directed evolution, a library is prepared of random mutations, mimicking evaluation. This is followed by a thorough screening and selection process. The semi-rational design combines the knowledge of the enzyme’s structure to know where a change is needed with the methodology of directed evolution to prepare a library of mutations within a specific region.