Synthesis of O-Linked Glycopeptides Using Enzymatic Catalysis
David Lim Final Ph.D. Seminar
Time & Place
Wed, 09 Mar 2016 12:00:00 NZDT in Room 531
All are welcome
Enzymes have many advantages over conventional synthetic methods. They can be used without the need of a protecting group strategy whilst maintaining high stereo- and regiochemistry. Over the past few decades, the use of enzymes has become prevalent because of their catalytic efficiency and their ability to be used under ‘green’ conditions.
In particular, the construction of glycosidic linkages using glycosidases is becoming increasingly widespread. However, the tendency for the product of the reverse hydrolysis to be a substrate for the natural enzymatic hydrolysis reaction has plagued this process with low yields. To remedy this, glycosynthases, class of mutant glycosidases, have been engineered to eliminate hydrolytic activity. In the presence of an activated donor substrate and an appropriate acceptor, glycosynthases are able to catalyze the formation of the glycosidic linkage, and not the hydrolysis leading to high yields.
This presentation will focus on the synthesis of activated O-glycan donors, and the expression, purification, and mutagenesis of glycosidase enzymes of the super-family GH101. Subsequent kinetic assays and glycosylation investigations with various acceptors using the wild-type and mutant enzymes will also be presented.