title: Efficient Chemoenzymatic Synthesis of an N-glycan Isomer Library.
abstract: Quantification, characterization and biofunctional studies of N-glycans on proteins remain challenging tasks due to complexity, diversity and low abundance of these glycans. The availability of structurally defined N-glycans (especially isomers) libraries is essential to help on solving these tasks. We reported herein an efficient chemoenzymatic strategy, namely Core Synthesis/Enzymatic Extension (CSEE), for rapid production of diverse N-glycans. Starting with 5 chemically prepared building blocks, 8 N-glycan core structures containing one or two terminal N-acetyl-D-glucosamine (GlcNAc) residue(s) were chemically synthesized via consistent use of oligosaccharyl thioethers as glycosylation donors in the convergent fragment coupling strategy. Each of these core structures was then extended to 5 to 15 N-glycan sequences by enzymatic reactions catalyzed by 4 robust glycosyltransferases. Success in synthesizing N-glycans with Neu5Gc and core-fucosylation further expanded the ability of enzymatic extension. High performance liquid chromatography with an amide column enabled rapid and efficient purification (>98% purity) of N-glycans in milligram scales. A total of 73 N-glycans (63 isomers) were successfully prepared and characterized by MS2and NMR. The CSEE strategy provides a practical approach for "mass production" of structurally defined N-glycans, which are important standards and probes for Glycoscience.
authors.affiliation: Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, 50 Decatur St SE, Atlanta, GA 30303.
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, 50 Decatur St SE, Atlanta, GA 30303.
authors.forename: Yunpeng
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, 50 Decatur St SE, Atlanta, GA 30303.
authors.forename: Cheng
authors.initials: C
authors.lastname: Ma
authors.affiliation: Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, 50 Decatur St SE, Atlanta, GA 30303.
authors.forename: Jingyao
authors.initials: J
authors.lastname: Qu
authors.affiliation: Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, 50 Decatur St SE, Atlanta, GA 30303.
authors.forename: Angie D
authors.initials: AD
authors.lastname: Calderon
authors.affiliation: Chemily, LLC, 58 Edgewood Ave NE, Atlanta, GA 30303.
authors.forename: Baolin
authors.initials: B
authors.lastname: Wu
authors.affiliation: Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, 50 Decatur St SE, Atlanta, GA 30303.
authors.forename: Na
authors.initials: N
authors.lastname: Wei
authors.affiliation: Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, 50 Decatur St SE, Atlanta, GA 30303.
authors.forename: Xuan
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, 50 Decatur St SE, Atlanta, GA 30303.
authors.forename: Yuxi
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, 50 Decatur St SE, Atlanta, GA 30303.
authors.forename: Zhongying
authors.initials: Z
authors.lastname: Xiao
authors.affiliation: Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, 50 Decatur St SE, Atlanta, GA 30303.
authors.forename: Jing
authors.initials: J
authors.lastname: Song
authors.affiliation: Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA 95616.
authors.forename: Go
authors.initials: G
authors.lastname: Sugiarto
authors.affiliation: Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA 95616.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA 95616.
authors.forename: Hai
authors.initials: H
authors.lastname: Yu
authors.affiliation: Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA 95616.
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, 50 Decatur St SE, Atlanta, GA 30303.
authors.forename: Peng George
authors.initials: PG
authors.lastname: Wang