Engineering glycosyltransferases into glycan binding proteins using a mammalian surface display platform

Abstract Traditional lectins exhibit broad binding specificity for cell-surface carbohydrates, and generating anti-glycan antibodies is challenging due to low immunogenicity. Nevertheless, it is necessary to develop glycan binding proteins for single-cell glycosylation pathway analysis. Here, we tes...

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Bibliographic Details
Main Authors: Ryoma Hombu, Lauren E. Beatty, John Tomaszewski, Sheldon Park, Sriram Neelamegham
Format: Article
Language:English
Published: Nature Portfolio 2025-07-01
Series:Nature Communications
Online Access:https://doi.org/10.1038/s41467-025-62018-z
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Summary:Abstract Traditional lectins exhibit broad binding specificity for cell-surface carbohydrates, and generating anti-glycan antibodies is challenging due to low immunogenicity. Nevertheless, it is necessary to develop glycan binding proteins for single-cell glycosylation pathway analysis. Here, we test the hypothesis that protein engineering of mammalian glycosyltransferases can yield glycan-binding proteins with defined specificity. Introducing an H302A mutation, based on rational design, into porcine ST3Gal1 abolishes its enzymatic activity, but results in a lectin that specifically binds sialylated core-2 O-linked glycans (Neu5Acα2-3Galβ1-3[GlcNAc(β1-6)]GalNAcα). To improve binding, we develop a mammalian cell-surface display platform to screen variants. One ST3Gal1 mutant (sCore2) with three mutations, H302A/A312I/F313S exhibits enhanced binding specificity. Spectral flow cytometry and tissue microarray analysis using sCore2 reveal distinct cell- and tissue-specific sialyl core-2 staining patterns in human blood cells and paraffin-embedded tissue sections. Overall, glycosyltransferases can be engineered to generate specific glycan binding proteins, suggesting that a similar approach may be extended to other glycoenzymes.
ISSN:2041-1723