Patent ID: 9689022
Date: 2017-06-27
CPC Classifications: C07H,C07K,C12N,C12Q,G01N

Claim:
1. A labeled post-translationally modified O-GlcNAc glycosylated protein linked with a galactosyl group having a chemical handle selected from the group consisting of a ketone group, azide group, alkyne group, and olefin group at 2-position of the galactosyl group, and wherein the chemical handle is further linked to a detection agent, and wherein said protein is obtained by transferring in an enzymatic reaction the galactosyl group having the chemical handle from a labeling agent comprising uridine diphosphate (UDP) and the galactosyl group to a post-translationally modified O-GlcNAc glycosylated protein in the presence of an enzyme selected from the group consisting of GalT glycosyl transferase and a mutant thereof, and covalently linking the detection agent to the chemical handle of the transferred galactosyl group; wherein the labeling agent has the formula wherein R is the chemical handle and wherein the detection agent comprises a reactive group capable of reacting with the chemical handle to form the covalent linkage.