Bacterial glycosyltransferase-mediated cell-surface chemoenzymatic glycan modification.

ABSTRACT: Chemoenzymatic modification of cell-surface glycan structures has emerged as a complementary approach to metabolic oligosaccharide engineering. Here, we identify Pasteurella multocida ?2-3-sialyltransferase M144D mutant, Photobacterium damsela ?2-6-sialyltransferase, and Helicobacter mustelae ?1-2-fucosyltransferase, as efficient tools for live-cell glycan modification. Combining these enzymes with Helicobacter pylori ?1-3-fucosyltransferase, we develop a host-cell-based assay to probe glycan-mediated influenza A virus (IAV) infection including wild-type and mutant strains of H1N1 and H3N2 subtypes. At high NeuAc?2-6-Gal levels, the IAV-induced host-cell death is positively correlated with haemagglutinin (HA) binding affinity to NeuAc?2-6-Gal. Remarkably, an increment of host-cell-surface sialyl Lewis X (sLeX) exacerbates the killing by several wild-type IAV strains and a previously engineered mutant HK68-MTA. Structural alignment of HAs from HK68 and HK68-MTA suggests formation of a putative hydrogen bond between Trp222 of HA-HK68-MTA and the C-4 hydroxyl group of the ?1-3-linked fucose of sLeX, which may account for the enhanced host cell killing of that mutant.

SUBMITTER: Hong S 

PROVIDER: S-EPMC6470217 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature