The Search for New Enzymes

In the enzyme design approach, as discussed in the first part of this chapter, one attempts to utilize the mechanistic understanding of chemical reactions and enzyme structure to create a new catalyst. This approach represents a largely academic research field aiming at fundamental understanding of biocatalysis. Indeed, the invention of functional artificial enzymes can be considered to be the ultimate test for any theory on enzyme mechanisms. Most artificial enzymes, to date, do not fulfill the conditions of catalytic efficiency and price per unit necessary for industrial applications. 

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Many of these have been demonstrated with a range of antibiotics and antibiotic precursors, although relatively few have been applied commercially. We have included a list of published examples in the form of an Appendix at the end of this chapter. We do not expect you to remember the details of this Appendix. It has been included as an potential for illustration of the potential to use enzymes to modify organic molecules like antibiotics. Usin9 It should be anticipated that, as enzyme technology develops and the search for new enzymes antibiotics continues, an increasing number of enzyme-based transformation will find commercial application. 

All these capabilities enable to address the search for new enzymes for specialty applications, such as thermostable and solvent resistance enzymes. A viscosity improving thermostable enzyme family (Pyrolase 160 and Pyrolase 200, the later working at higher temperatures) was designed for use in deep and high temperature oil wells. Sales of this product commenced in January 1999, but were discontinued later. 

Enzyme and Gene Databases, Bioinformatics and the Search for New Enzymes... 

The search for new antivkal agents is ongoing and extensive not all vimses have been included here, and new vimses pathogenic to humans will continue to be identified. Novel nucleosides as weU as nonnucleosidic compounds which possess greater potency and enzymic specificity for the future treatment of both acute and persistent human vkal infection will continue to be discovered. 

A search for new enzymes should be continued. Nature proves to be still very unpredictable and sometimes startling discoveries can be made, which are, for example, connected with finding new enzymes of unexpected activity. Phosphotriesterases are the best examples as they catalyse the transformation which is unknown in living systems. 

Flavonoid glycosides and their esters are an important group of natural compounds isolated from plants. They are widely used in pharmaceutical, cosmetic, and food preparations, and it is therefore not surprising that the search for new derivatives with improved antioxidant and antimicrobial activity, or-more sim-ply-with more suitable physico-chemical properties for specific applications (i.e., increased stability and/or solubility), has identified enzyme-catalyzed regioselective esterification as a particularly promising approach to the target molecules [21a],... 

In the age of recombinant DNA technology and genetic engineering-based methodologies, why is the search for new microorganisms or new enzyme activities still so important ... 

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