The recognition motif of the glycoprotein-folding sensor enzyme UDP-Glc:glycoprotein glucosyltransferase.

摘要: The folding of glycoproteins is primarily mediated by a quality control system in the ER, which UDP-Glc:glycoprotein glucosyltransferase (UGGT) serves as "folding sensor". In this system, client are delivered to UGGT after trimming their innermost glucose residue glucosidase II, releases them from lectin chaperones calnexin (CNX) and calreticulin (CRT). inactive against folded proteins, allowing proceed Golgi apparatus for further processing complex- or hybrid-type glycoforms. On other hand, enzyme efficiently glucosylates incompletely monoglucosylated structures, providing with an opportunity interact CNX/CRT. order clarify mode enzyme's substrate recognition, we conducted structure-activity relationship study using series synthetic probes. inhibitory activities various glycans suggest that has strong affinity core pentasaccharide (Man3GlcNAc2) high-mannose-type glycans. Our comparison reactivity acceptors have been modified aglycons supports hypothesis recognizes hydrophobic region glycoproteins. Moreover, discovered fluorescently labeled substrates will be valuable highly sensitive detection activity.