New enzymes for cheaper glycosylation
Glycosylation, the addition of a sugar molecule to an acceptor compound, is an important industrial process to create new pharmaceutical, cosmetic or flavourant compounds. However, the reaction needs to be catalysed by often expensive and inefficient chemical catalysts. The EU-funded NOVOSIDES (Novel biocatalysts for the production of glycosides) project was set up to address this problem. Project researchers aimed to engineer stable and efficient enzymes as alternatives to current chemical catalysts. Researchers began by screening public databases for transglycosidases, glycoside phosphorylases and glycoside hydrolases, all enzymes that can transfer a glycosyl group. More than 50 candidate enzymes were chosen and screened for specificity, stability and glycosylation activity, several of which were newly discovered enzyme reactions. NOVOSIDES developed a unique high-throughput screening method specifically for this. A genetic engineering approach called directed evolution was used to improve the reaction rates and overall stability of the most promising enzymes. This produced several stable, highly-active enzymes that NOVOSIDES has protected with patents. These enzymes were produced en masse at pilot plants connected with the consortium. The process was scaled up to produce more than a kilogram of pure enzyme. Life-cycle analysis revealed that the environmental impact was nine times lower than the conventional chemical process. NOVOSIDES made several of these enzymes available through one of its commercial partners. The results of this research initiative will have a major impact on the chemical synthesis industry, making it both more productive and more sustainable.
Keywords
Enzymes, glycosylation, chemical catalysts, biocatalysts, glycosides, directed evolution
