Glucosyltransferase-catalyzed synthesis

JONES, P.R., M0LLER, B.L., H0J, P.B. The UDP-glucose p-Hydroxymandelonitrile-O-glucosyltransferase that catalyzes the last step in synthesis of the cyanogenic glucoside dhurrin in Sorghum bicolor, J. Biol. Chem., 1999, 274,35483-35491. 

Reaction 4.2 is catalyzed by starch synthase (E.C. 2.4.1.21 ADP-glucose 1,4-a-D-glucan 4-a-glucosyltransferase). Similar reactions are noted for glycogen synthesis in cyanobacteria and other bacteria,24 26 but the enzyme is referred to as glycogen synthase (also E.C. 2.4.1.21). 

The synthesis of BOA-6-O-glucoside is catalyzed by constitutive enzymes that may be upregulated. A glucosyltransferase that accepted BOA-6-OH as a substrate was measurable in protein extracts of corn roots harvested from control plants. Detoxification via glucoside carbamate synthesis is inducible and seems to be more complicated than simple A/-glucosylation (data unpublished). The biosynthesis of the compounds is part of our ongoing research. 

Ichikawa S, Sakiyama H, Suzuki G, Hidari KI, Hirabayashi Y (1996) Expression cloning of a cDNA for human ceramide glucosyltransferase that catalyzes the first glycosylation step of glycosphingolipid synthesis. Proc Natl Acad Sci USA 93 4638 643... 

---