Chemoenzymatic Assembly of Bacterial Glycoconjugates for Site-Specific Orthogonal Labeling.
The cell surfaces of bacteria are replete with diverse glycoconjugates that play pivotal roles in determining how bacteria interact with the environment and the hosts that they colonize. Studies to advance our understanding of these interactions rely on the availability of chemically defined glycoconjugates that can be selectively modified under orthogonal reaction conditions to serve as discrete ligands to probe biological interactions, in displayed arrays and as imaging agents. Herein, enzymes in the N-linked protein glycosylation (Pgl) pathway of Campylobacter jejuni are evaluated for their tolerance for azide-modified UDP-sugar substrates, including derivatives of 2,4-diacetamidobacillosamine and N-acetylgalactosamine. In vitro analyses reveal that chemoenzymatic approaches are useful for the preparation of undecaprenol diphosphate-linked glycans and glycopeptides with site-specific introduction of azide functionality for orthogonal labeling at three specific sites in the heptasaccharide glycan. The uniquely modified glycoconjugates represent valuable tools for investigating the roles of C. jejuni cell surface glycoconjugates in host pathogen interactions.
Departments of Biology and Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
Vinita
V
Lukose
Departments of Biology and Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
Garrett
G
Whitworth
Department of Biochemistry, Duke University Medical Center , Durham, North Carolina 27710, United States.
Ziqiang
Z
Guan
Departments of Biology and Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
Barbara
B
Imperiali
D016123:Campylobacter jejuni / Q000201:enzymology*; D002240:Carbohydrate Sequence; D006001:Glycoconjugates / Q000138:chemical synthesis* / Q000378:metabolism*; D006031:Glycosylation; D054884:Host-Pathogen Interactions; D006801:Humans
D006001:Glycoconjugates