# Convergent Chemoenzymatic Synthesis of Glycopeptides and Glycoproteins

> **NIH NIH R01** · UNIV OF MARYLAND, COLLEGE PARK · 2021 · $307,955

## Abstract

Project Summary/Abstract
The objectives of the proposed research are to develop facile chemoenzymatic methods for synthesizing
homogeneous N-glycoproteins of biomedical significance. A major problem in functional glycomics studies
and glycoprotein therapeutic applications is the lack of efficient methods to produce glycan-defined
glycoproteins. We have recently developed a chemoenzymatic method that exploits the transglycosylation
activity of a class of endoglycosidases (ENGases) that enables the “native ligation” between free glycan and
GlcNAc-tagged protein to form homogeneous glycoproteins with native glycosidic linkage. We have discovered
novel endoglycosidase-based mutants, the glycosynthases, that are capable of using highly active glycan
oxazolines for transglycosylation but lack the product hydrolysis activity. The glycosynthase-catalyzed native
ligation permits independent manipulations of the sugar and protein portions and provides a highly convergent
approach to glycoprotein assembly. This method has been successfully applied for the synthesis of a series of
complex glycopeptides such as the HIV-1 glycopeptide antigens and CD52 glycoproteins. It has also been
explored for glycan remodeling of recombinant glycoproteins including human erythropoietin (EPO) and
therapeutic antibodies. In this application, we aim at improving the chemoenzymatic method, expanding its
scope, and speeding up its application as a general method for the synthesis of homogeneous glycoforms of
glycoproteins. Four specific aims will be pursued to achieve the goals. The first two aims are focused on
generating new endoglycosynthases from bacterial endoglycosidases and novel -fucoligases from an array of
-fucosidases with distinct (1,6, 1,3/1,4, and 1,2)-fucosidic linkages; the third aim is to develop an E. coli
co-expression system to produce GlcNAc- and Glc-containing proteins that will serve as the key precursor for a
combined synthesis of glycosylated therapeutic proteins with a goal of enhancing the serum half-life of
therapeutic proteins; and the fouth aim is to establish a method for glycosylation remodeling of lysosomal
enzymes such as the recombinant human -glucosidase with mannose-6-phosphate (M6P) oligosaccharides
for improving their cellular uptake in enzymatic replacement therapy. A successful completion of the proposed
research will significantly expand the scope of the chemoenzymatic method; provide new enabling
technologies to the community of glycobiology and biotechnology; and speed up the applications of the
chemoenzymatic method for improving the efficacy of therapeutic proteins.

## Key facts

- **NIH application ID:** 10145008
- **Project number:** 5R01GM080374-13
- **Recipient organization:** UNIV OF MARYLAND, COLLEGE PARK
- **Principal Investigator:** LAI-XI WANG
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $307,955
- **Award type:** 5
- **Project period:** 2007-06-01 → 2024-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10145008

## Citation

> US National Institutes of Health, RePORTER application 10145008, Convergent Chemoenzymatic Synthesis of Glycopeptides and Glycoproteins (5R01GM080374-13). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10145008. Licensed CC0.

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