AUTHOR=Dolan Jonathan P. , Machin Darren C. , Dedola Simone , Field Robert A. , Webb Michael E. , Turnbull W. Bruce 

TITLE=Synthesis of cholera toxin B subunit glycoconjugates using site-specific orthogonal oxime and sortase ligation reactions

JOURNAL=Frontiers in Chemistry

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.958272

DOI=10.3389/fchem.2022.958272

ISSN=2296-2646

ABSTRACT=<p>The chemoenzymatic synthesis of a series of dual N- and C-terminal–functionalized cholera toxin B subunit (CTB) glycoconjugates is described. Mucin 1 peptides bearing different levels of Tn antigen glycosylation [MUC1(Tn)] were prepared <italic>via</italic> solid-phase peptide synthesis. Using sortase-mediated ligation, the MUC1(Tn) epitopes were conjugated to the C-terminus of CTB in a well-defined manner allowing for high-density display of the MUC1(Tn) epitopes. This work explores the challenges of using sortase-mediated ligation in combination with glycopeptides and the practical considerations to obtain high levels of conjugation. Furthermore, we describe methods to combine two orthogonal labeling methodologies, oxime- and sortase-mediated ligation, to expand the biochemical toolkit and produce dual N- and C-terminal–labeled conjugates.</p>