Efficient Chemical Synthesis and Folding of Mirror‐Image Tropomyosin Receptor Kinase A Using the Strategy of Removable Glycosylation Modification†

Abstract

Comprehensive SummaryThe strategy of removable glycosylation modification was used to overcome the low‐efficiency problem encountered in the chemical synthesis of the mirror‐image D‐version of the immunoglobulin (Ig)‐like domain of tropomyosin receptor kinase A (DlgCTrkA), a protein molecule needed for mirror‐image screening of D‐peptide ligands targeting this cell membrane receptor. It was found that O‐linked‐β‐N‐acetyl‐D‐glucosamine (O‐GlcNAc) modification at DSer312, or DSer320 can significantly improve the efficiency of DlgCTrkA synthesis and folding, while O‐GlcNAc modification at DSer330 showed barely any improvement. This study provides a new example demonstrating the power of the removable glycosylation modification strategy in the chemical synthesis and folding of difficult‐to‐obtain proteins. It also presents evidence that removable glycosylation modification at different sites would significantly affect the efficiency of protein folding promoted by this strategy.