Tailor-Made Proteins

Nearly all objects we consider to be complex are manmade and the result of a rational target-oriented design. Conversely, natural living organisms greatly surpass technical items in terms of complexity without being rationally constructed. They are the result of a long history of evolution, lacking any conscious plan. The strong ‘creative’ force behind this development was recognised some 150 years ago, and became known as Darwinian evolution. The basic principle for the rise of increased complexity and adaptation to a given environment through this process is based on three simple prerequisites: replication, mutation and selection. This strategy is, in fact, so powerful that it outperforms today’s capabilities for rational design by some distance.

Most complex functions of an organism are controlled by proteins: sub-microscopic nanomachines which fulfil their function through a unique three-dimensional structure defined by a specific sequence of 20 different amino acid building blocks. With today’s analytical tools it is easy to determine the amino acid sequence of a protein. It is also possible to resolve the spatial structure of a protein. Still, there is a missing analytical link between sequence and structure as it is not possible to deduce one feature from the other. This is caused by the mathematical complexity of the protein folding problem (attainment of three-dimensional structure) and limitations in today and tomorrow’s computer power.

Proteins are becoming increasingly important in many areas of industry. Pharma exercises demands for recombinant therapeutic proteins with an estimated annual market value in 2008 of US$70 billion to fight anaemia, haemophilia, multiple sclerosis, leukaemia and viral infections, to mention just a few (Frost & Sullivan, BioPharm International, WestLB Equity Research). Food industry uses proteins for baking, juice production, brewing, dairy applications and others. Enzymes (catalytic proteins) are common ingredients in modern detergents and are widely used in pulp and paper processing, textile production and animal feed additives.