Efficient Chemical Synthesis and Folding of Mirror‐Image Tropomyosin Receptor Kinase A Using the Strategy of Removable Glycosylation Modification<sup>†</sup>
Tongyue Wang, Weiwei Shi, Guo‐Chao Chu, Yi‐Ming Li
Abstract
Comprehensive Summary The 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 ( D lgC TrkA ), 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 D Ser 312 , or D Ser 320 can significantly improve the efficiency of D lgC TrkA synthesis and folding, while O‐GlcNAc modification at D Ser 330 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.