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We use the combination of organic and enzymatic strategies to generate the repository of mammalian glycans and glycopeptides, and employ these structures to develop glycomics tools to study carbohydrate-protein interactions. We also use molecular biology, biochemistry, and chemical biology technologies to understand the biosynthesis of bacterial glycans and glycoconjugates with a focus on antibiotic-resistant pathogens, and synthesize length-defined bacterial polysaccharide to develop next-generation carbohydrate-based vaccines.

1. Streamline the Synthesis of Complex Glycans and Glycoconjugates

Carbohydrates are directly involved in normal physiology and in the etiology of every major disease afflicting mankind. Elucidation of their functions and the mechanism of related biological processes demands diverse structurally well-defined glycoforms. Owning to the inherent complexity and diversity, isolation of natural glycans in sufficient amounts remains a formidable challenge, and synthesis of complex glycans with designated linkages continues to pose difficulties despite recent advances in the field. Takes advantage of organic chemistry in gram scale synthesis of glycan core structures, and the stereo- and regio-selectivity of enzymatic synthesis, we are developing chemoenzymatic approaches to streamline the production of complex glycans, with a focus on N-glycans, N-glycopeptides, O-glycans, O-glycopeptides, and glycosaminoglycans.

Related Publications

Gao-Lan Zhang, Madhusudhan Reddy Gadi, Xikai Cui, Ding Liu, Jiabin Zhang, Varma Saikam, Christopher Gibbons, Peng G. Wang & Lei Li*. Protecting-group-free S-glycosylation towards thioglycosides and thioglycopeptides in water. Green Chem, 2021,

Chen, Shuaishuai Wang, Madhusudhan Reddy Gadi, He Zhu Fei Liu, Chang-Cheng Liu, Lei Li*, Fengshan Wang*, Peixue Ling* & Hongzhi Cao*. Enzymatic modular synthesis and microarray assay of poly-N-acetyllactosamine derivatives. Chem Commun, 2020, 56, 7549-7552.

Shuaishuai Wang, Qing Zhang, Congcong Chen, Yuxi Guo, Madhusudhan Reddy Gadi, Jin Yu, Ulrika Westerlind, Yunpeng

Liu, Xuefeng Cao, Peng G. Wang* & Lei Li*. Facile chemoenzymatic synthesis of O-mannosyl glycans. Angew Chem Int Ed, 2018, 57, 9268-9273.

Lei Li, Yunpeng Liu, Cheng Ma, Jingyao Qu, Angie D. Calderon, Baolin Qu, Na Wei, Xuan Wang, Yuxi Guo, Zhongying Xiao, Jing Song, Go Sugiarto, Yanhong Liu, Hai Yu, Xi Chen & Peng G. Wang. Efficient chemoenzymatic synthesis of an N-glycan isomer library. Chem Sci, 2015, 6, 5652-5661.

Related Funding:

U01GM116263 from NIGMS         Li        Ended
Role: Principal Investigator
Title: Chemoenzymatic synthesis O-glycans and O-glycopeptides


R44GM123820 from NIGMS         MPI (Zhang/Li)          1/2021 -- 1/2024
: Principal Investigator

Title: A 5K comprehensive glycan microarray

2. Develop Glycomics Tools to Probe Glycans and Elucidate their Functions

Carbohydrates on glycoproteins and cell surfaces contain crucial biological information, which is decoded by glycan-binding proteins (GBPs). A major technical breakthrough in glycoscience to facilitate decode glycan functions and recognition was the development of glycan microarrays, in which picograms of defined glycans are immobilized on a solid surface and interrogated by a GBPs. We are developing such tools and applying them in screening cancer autoantibodies and elaborating the evolution and mutations of Influenza viruses. We are also interested in developing mass-spectrometry based tools to profile and quantify glycans on proteins and cells, as well as probe specific glycoepitopes on cell surfaces. 

Related Publications

Shuaishuai Wang, Ding Liu, Jingyao Qu, He Zhu, Congcong Chen, Christopher Gibbons, Harmon Greenway, Peng Wang, Roni J. Bollag, Kebin Liu & Lei Li*. Streamlined Subclass-Specific Absolute Quantification of Serum IgG Glycopeptides Using Synthetic Isotope-Labeled Standards. Anal Chem, 2021, 93, 4449–4455.

Cheng Ma, Ding Liu, Dong Li, Junping Zhang, Xiao-Qian Xu, He Zhu, Xiufeng Wan, Carol H. Miao, Barbara A. Konkle, Philip Onigman, Weidong Xiao* & Lei Li*. Comprehensive N- and O-glycosylation mapping of human coagulation factor V. J Thromb Haemost, 2020, doi: 10.1111/jth.14861.

He Zhu, Shuaishuai Wang, Ding Liu, Lang Ding, Congcong Chen, Yunpeng Liu Zhigang Wu, RoniBollag, Kebin Liu, Jun Yin, Cheng Ma, Lei Li* & Peng George Wang*. Identifying sialylation linkages at the glycopeptide level by glycosyltransferase labeling assisted mass spectrometry (GLAMS). Anal Chem, 2020, 92, 6297-6303.

Lei Li*, Wanyi Guan, Gaolan Zhang, Zhigang Wu, Hai Yu, Xi Chen & Peng George Wang. Microarray analyses of closely related glycoforms reveal different accessibilities of glycan determinants on N-glycan branches. Glycobiology, 2020, 30, 334-345.

Related Funding:

U54HL142019 from NHLBI         (MPI: Xiao/Li/Miao)            06/2019 – 04/2023

Role: Principal Investigator of Project 2             

Title: Center for the Investigation of Factor VIII Inhibitors and Glycosylation

Goal: A major obstacle in treating hemophilia A is that ~25% of patients develop neutralizing anti-factor VIII (FVIII) antibodies (inhibitors) following protein replacement therapy. Using glycan microarray and other glycomics tools, we aims to define specific immunologic trigger by glycosylation and its associated mechanisms, leading to prevention or elimination of FVIII inhibitors.

3. Towards Next Generation Surface Carbohydrate-based Vaccines against Infectious Bacteria

Bacterial infection is one of the major health problems over the world, and increasing cases of antibiotic resistance of many types of bacteria have become a top threaten to human health. For example, antibiotic resistant Clostridioides difficile is causing 453,000 infections and 29,000 deaths per year in USA. All bacterial present a dense layer of carbohydrate on their cell surface. Some glycans were proved to elicit specific immune responses. Our research interests are at the biosynthesis of bacterial glycans including CPS and LPS, as well as glycoconjugates. We are using molecular and synthetic techniques to elaborate the biosynthetic pathways, and targeting critical steps to develop inhibitors and mimics as novel vaccines and therapeutics, and synthesizing length-defined bacterial polysaccharide to develop next generation carbohydrate vaccines. 

Related Publications

Zhongrui Ma, Gaolan Zhang, Madhusudhan Reddy Gadi, Yuxi Guo, Peng Wang & Lei Li*. Clostridioides difficile cd2775 encodes a unique mannosyl-1-phosphotransferase for polysaccharide II biosynthesis. ACS Infect Dis, 2020, 6, 680-686

Lei Li, Robert L. Woodward, Weiqing Han, Jingyao Qu, Jing Song, Cheng Ma & Peng G. Wang. Chemoenzymatic synthesis of bacterial polysaccharide repeating unit-pyrophosphate-undecaprenyl and analogues. Nat Protoc, 2016, 11, 1280-1298.

Tiehai Li, Liuqing Wen, Adriel Williams, Baolin Wu, Lei Li, Jingyao Qu, Jeffrey Meisner, Zhongying Xiao, Junqing Fang & Peng G. Wang. Chemoenzymatic synthesis of ADP-D-glycero-b-D-manno-heptose and study of the substrate specificity of HldE.

Bioorg Med Chem, 2014, 22, 1139-1147.

Robert Woodward†, Wen Yi†, Lei Li†, Guohui Zhao†, Hironobu Eguchi†, Perali R. Sridhar, Hongjie Guo, Jing K. Song, Edwin Motari, Li Cai, Patrick Kelleher, Xianwei Liu, Weiqing Han, Wenpeng Zhang, Yan Ding, Mei Li & Peng G. Wang. In vitro bacterial polysaccharide biosynthesis: Defining the functions of Wzy and Wzz. Nat Chem Biol, 2010, 6, 418-423.

Related Funding:

U01GM125288 from NIGMS         (MPI: Yu/Kiessling/Li)        09//2017 – 07//2022
Role: Principal Investigator
Title: Chemoenzymatic synthesis of bacterial polysaccharides
Goal: Bacterial polysaccharides have broad applications in vaccine design, diagnosis, modulating the immune system, and probing carbohydrate-binding proteins. The project will develop effective chemoenzymatic approaches to access a diverse array of bacterial polysaccharides. 

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