INTRACELLULAR MODIFICATIONS OF HUMAN APOLIPOPROTEIN E

人载脂蛋白 E 的细胞内修饰

• 批准号: 7369267
• 负责人: VASSILIS I ZANNIS
• 金额: $ 0.69万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7369267
• 关键词: INTRACELLULAR; MODIFICATIONS; HUMAN; APOLIPOPROTEIN

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Human plasma apolipoprotein E (apoE) is responsible for the clearance of lipoprotein remnants and has been implicated in diseases like familial type III hyperlipoproteinemia and Alzheimer?s disease. It is known to be initially sialylated after synthesis and later desialylated in the plasma. Studies of synthesis and intracellular modification of apoE by HepG2 cells have shown modified apoE isoproteins corresponding to the sialo apoE forms with two, four or six sialic acid residues. The expected O-glycosylation site needs to be confirmed and the kind of modification to be characterized by mass spectrometry. From a tryptic digest of apoE, one disialylated glycan could be detected at the expected position by LC-MS/MS, and was then also found by standard MALDI TOF MS. It is planned to isolate the glycopepitde(s) with the help of lectins. Vibrationally cooled (VC) MALDI FT-MS might help to detect higher sialylated, more instable homologues.

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。人血浆载脂蛋白E （apoE）负责脂蛋白残留物的清除，并与家族性III型高脂蛋白血症和阿尔茨海默病等疾病有关。年代的疾病。已知它在合成后最初唾液化，随后在血浆中去唾液化。HepG2细胞对载脂蛋白e的合成和细胞内修饰的研究表明，修饰的载脂蛋白e同工蛋白与具有两个、四个或六个唾液酸残基的唾液载脂蛋白e形式相对应。预期的o -糖基化位点需要确定，修饰的种类需要用质谱法进行表征。从apoE的胰蛋白酶消化中，LC-MS/MS可以在预期位置检测到一个二二化的聚糖，然后通过标准MALDI TOF MS也可以找到。计划在凝集素的帮助下分离糖copepitde。振动冷却（VC） MALDI FT-MS可能有助于检测高度唾液化，更不稳定的同源物。