Protein design refers to the ability to alter protein structure to achieve the desired protein function. In order to increase the solubility, stability or ability to crystallize of a given protein, we can use a protein compaction technology based on the deletion of the protein’s non-essential floppy loops. 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.