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.

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子弹和调查员（PI）可能已经从其他NIH来源获得了主要资金，因此可以在其他清晰的条目中代表。列出的机构适用于该中心，这不一定是调查员的机构。人血浆载脂蛋白E（APOE）负责清除脂蛋白残留物，并与家族性III型高脂蛋白血症和阿尔茨海默氏病等疾病有关。众所周知，它最初是在合成后溶解的，后来在等离子体中进行了溶解。 HEPG2细胞对APOE的合成和细胞内修饰的研究表明，对应于具有两个，四个或四个唾液酸残基的Sialo ApoE形式的APOE异蛋白。需要确认预期的O-糖基化位点，并以质谱为特征的修饰。从APOE的胰蛋白酶消化中，可以通过LC-MS/MS在预期的位置检测到一个有害的聚糖，然后由Standard Maldi TOF MS发现。计划在凝集素的帮助下分离糖磷酸。振动冷却（VC）MALDI FT-MS可能有助于检测更高的溶解的，更稳定的同源物。