earticle

영어

Glycodiversification and glycorandomization, invaluable tools for generating biochemical diversity, can be catalyzed by flexible glycosyltransferases (GTs), which attach various activated sugar “donors” onto different type of “acceptor” molecules. Among discovered and successfully developed protein engineering techniques, creation of hybrid protein have been evaluated as very powerful approach to produce enzyme with new activity. Theoretically, hybrid protein was built up by different fragments from various parent molecules. Particularly, engineered GTs have been used as wonderful catalysts for making new glycosylated compound, for example, the generation of new hybrid glycopeptides or glycosylation of scopoletin by GT from Arabidopsisthalianaorproducing novel urdamycin derivatives, etc. Applying protein modeling, we have constructed a hybrid protein HT1 that is composed of DnrS-derived N-terminal and DesVII-originated C-terminal. The enzyme activity was tested using various activated sugar produced Escherichia coli system (such as TDP-rhamnose, UDP-xylose and UDP-6-deoxy-allose) in combination with the transformation of phenolic substrate (flavonoid, stilbene, quinone, etc). The initial result showed that hybrid protein significant change in regio-specific activity in comparison with parent molecule (DnrSandDesVII), particularly, enabling produce flavonol and flavanone-O-rhamnoside such as quercetin, kaempferol, myricetin, andnaringenin-O-rhamnoside. The experiment of glyco-diversification is continuously carrying out to determine the level of enzyme’s promiscuity and which type of the most favorite substrate was recruited. Therefore, the chimeric protein HT1 is apromising tool to divert the natural products. Furthermore it is possible to improve or alter enzyme activity by domain swapping from far related glycosyltransferases.