Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043 Japan.
J Am Chem Soc. 2012 May 2;134(17):7238-41. doi: 10.1021/ja3013177. Epub 2012 Apr 17.
Biosynthesis of glycoproteins in the endoplasmic reticulum employs a quality control system, which discriminates and excludes misfolded malfunctional glycoproteins from a correctly folded one. As chemical tools to study the glycoprotein quality control system, we systematically synthesized misfolded homogeneous glycoproteins bearing a high-mannose type oligosaccharide via oxidative misfolding of a chemically synthesized homogeneous glycopeptide. The endoplasmic reticulum folding sensor enzyme, UDP-glucose:glycoprotein glucosyltransferase (UGGT), recognizes a specific folding intermediate, which exhibits a molten globule-like hydrophobic nature.
内质网中糖蛋白的生物合成采用了质量控制系统，该系统能够区分和排除错误折叠的功能失调的糖蛋白与正确折叠的糖蛋白。作为研究糖蛋白质量控制系统的化学工具，我们通过化学合成的均一糖肽的氧化错误折叠，系统地合成了带有高甘露糖型寡糖的错误折叠均一糖蛋白。内质网折叠传感器酶，UDP-葡萄糖：糖蛋白葡糖基转移酶（UGGT），识别特定的折叠中间体，其表现出类似无规卷曲的疏水性。
