N‐Terminal Modification of Gly‐His‐Tagged Proteins with Azidogluconolactone

Site-specific protein modifications are vital for biopharmaceutical drug development. Gluconoylation is a non-enzymatic, post-translational modification of N-terminal HisTags. We report high-yield, site-selective in vitro α-aminoacylation peptides, glycoproteins, antibodies, and virus-like particles (VLPs) with azidogluconolactone at pH 7.5 1 h. Conjugates slowly hydrolyse, but diol-masking borate esters inhibits reversibility. In an example, we multimerise azidogluconoylated SARS-CoV-2 receptor-binding domain (RBD) onto VLPs via click-chemistry, to give COVID-19 vaccine. Compared yeast antigen, HEK-derived RBD was immunologically superior, likely due observed differences glycosylation. show the benefits ordered over randomly oriented multimeric antigen display, by demonstrating single-shot seroconversion best virus-neutralizing antibodies. Azidogluconoylation simple, fast robust chemistry, should accelerate research