Patent ID: 8524444

Claim:
A method of detecting the level of O-glycosylation of a polypeptide, the method comprising: (a) contacting a glucosyltransferase enzyme and a sugar donor with a molecule comprising a detectably labeled polypeptide having: (i) an O-glycosylation site and (ii) a specific protease cleavage site positioned in the polypeptide such that the rate of cleavage of the polypeptide by the specific protease at the specific protease cleavage site is different when the polypeptide is O-glycosylated at the glycosylation site than when the polypeptide is not O-glycosylated at the glycosylation site, wherein the detectable label is positioned in the polypeptide such that a change in the amount of detectable label correlates with cleavage of the polypeptide by the specific protease; (b) adding to the contacted polypeptide the specific protease that cleaves at the specific protease cleavage site of the polypeptide; and, (c) monitoring the rate of cleavage of the polypeptide, thereby detecting the level of O-glycosylation of the polypeptide.