title: Rational design of a β-glycosidase with high regiospecificity for triterpenoid tailoring.
abstract: Triterpenoids with desired glycosylation patterns have attracted considerable attention as potential therapeutics for inflammatory diseases and various types of cancer. Sugar-hydrolyzing enzymes with high substrate specificity would be far more efficient than other methods for the synthesis of such specialty triterpenoids, but they are yet to be developed. Here we present a strategy to rationally design a β-glycosidase with high regiospecificity for triterpenoids. A β-glycosidase with broad substrate specificity was isolated, and its crystal structure was determined at 2.0 Å resolution. Based on the product profiles and substrate docking simulations, we modeled the substrate binding modes of the enzyme. From the model, the substrate binding cleft of the enzyme was redesigned in a manner that preferentially hydrolyzes glycans at specific glycosylation sites of triterpenoids. The designed mutants were shown to produce a variety of specialty triterpenoids with high purity.
authors.affiliation: Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daehak-ro, Yuseong-gu, Daejeon, 305-701 (Korea).
authors.forename: Sang Jin
authors.initials: SJ
authors.lastname: Park
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Choi
authors.forename: Hyun-Ho
authors.initials: HH
authors.lastname: Kyeong
authors.forename: Song-Gun
authors.initials: SG
authors.lastname: Kim
authors.forename: Hak-Sung
authors.initials: HS
authors.lastname: Kim
mesh_terms: D000192:Actinomycetales / Q000201:enzymology / Q000235:genetics; D055162:Biocatalysis; D008958:Models, Molecular; D008968:Molecular Conformation; D009154:Mutation; D013379:Substrate Specificity; D014315:Triterpenes / Q000737:chemistry / Q000378:metabolism*; D001617:beta-Glucosidase / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D014315:Triterpenes; D001617:beta-Glucosidase
keywords: binding mode; glycosides; rational design; regiospecificity; terpenoids