A continuous protection strategy using glycan tags to suppress aggregation of hydrophobic peptides

We investigated combination of the glycan tag, peptide-based tag, denaturing agents, and acidic conditions to efficiently prepare highly hydrophobic peptides using E. coli expression. The hydrophilic glycan tag suppressed aggregation of long polypeptides, even when a conventional small ubiquitin-like modifier (SUMO) tag is not sufficient. Moreover, SUMO protease properly recognized and cleaved the SUMO tag in the presence of the additional glycan tag. The finding of the continuous protection strategy enabled efficient preparation of aggregation-prone peptides for semisynthesis of proteins.