Applications of high-value proteins

Proteins used in industrial enzyme technology, e.g. detergent proteinases or enzymes applied in the food industry, are in most cases rather crude preparations and usually mixtures of different enzymes. In contrast, there are a number of commercial applications where highly purified (and therefore high-value) proteins are needed. Examples are:

• Analytical enzymes and antibodies: Used in medical diagnostics, food analysis, as well as biochemical and molecular biological analysis (see Section 21.2).

• Enzymes used as tools in genetic engineering technology: Gene technology has become possible through the availability of highly purified restriction endonucleases, DNA and RNA polymerases, nucleases and modifying enzymes (see Chapters 4 and 5). Similarly, glycohydrolases and glycosyl transferases are used increasingly in glycobiotechnology in order to modify the sugar residues of glycoproteins.

• Therapeutic proteins: Growth factors, antibodies and enzymes are used as the active drug ingredients for the treatment of diseases (see Section 21.3).

Furthermore, proteins with proven or supposed biological relevance in pathomechanisms are needed as targets for the search of new ligands (agonists or antagonists) or inhibitors and for X-ray or nuclear magnetic resonance (NMR) structural analysis in order to design novel interacting compounds by structure-based molecular modelling. This requires the production of these proteins on a relatively small scale (10 to 100 mg), but often with high purity depending on the intended use.

Analytical enzymes

Enzymes are highly specific both in the reaction catalysed as well as in their choice of substrates.