Protein Design

Protein design refers to the ability to alter protein structure to achieve the desired protein function. Of the two classes of proteins (binding proteins and catalytic proteins), catalytic proteins, or so-called enzymes, are of particular importance to chemical processing because they can be used as chemical catalysts. Enzymes are able to catalyze a broad range of chemical reactions with exquisite specificity and selectivity (stereo-, regio-, and chemo-). In addition, most enzymes are quite efficient catalysts and operate at mild conditions, resulting in less energy consumption. In the past several decades, enzymes have been increasingly employed to synthesize chemicals and materials in the pharmaceutical, chemical, food and agriculture industries. However, the number and diversity of the applications are modest compared to the total number of enzymes identified so far ( 4000 enzymes). One main reason for this discrepancy is that naturally occurring enzymes are often not functionally optimal under process conditions in terms of their activity, stability, specificity, and selectivity. To overcome this limitation, tailor-made biocatalysts must be developed by protein design. This entry discusses the molecular tools of protein design and their applications in engineering naturally occurring enzymes into commercially viable biocatalysts for chemical processing. However, their applications in the development of therapeutic proteins and monoclonal antibodies are not discussed.