INTRACELLULAR MODIFICATIONS OF HUMAN APOLIPOPROTEIN E

人载脂蛋白 E 的细胞内修饰

• 批准号: 7602002
• 负责人: VASSILIS I ZANNIS
• 金额: $ 0.22万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-03 至 2008-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7602002
• 关键词: Alzheimer' s Disease; Apolipoprotein E; Apolipoproteins; Cells; Computer Retrieval of Information on Scientific Projects Database; Disease; Funding; Glycopeptides; Grant; Homologous Gene; Human; Hyperlipoproteinemia Type III; Institution; Lectin; Lipoproteins; Mass Spectrum Analysis; Modification; Plasma; Polysaccharides; Positioning Attribute; Research; Research Personnel; Resources; Sialic Acids; Site; Source; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Standards of Weights and Measures; United States National Institutes of Health; glycosylation

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 glycopeptide(s) with the help of lectins. Vibrationally cooled (VC) MALDI FT-MS may help to detect higher sialylated, more instable homologs.

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目和 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 人血浆载脂蛋白 E (apoE) 负责清除脂蛋白残余物，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。已知它在合成后最初被唾液酸化，随后在血浆中被去唾液酸化。 HepG2 细胞对 apoE 的合成和细胞内修饰的研究表明，修饰的 apoE 同蛋白对应于具有两个、四个或六个唾液酸残基的 sialo apoE 形式。需要确认预期的 O-糖基化位点，并通过质谱来表征修饰类型。从 apoE 的胰蛋白酶消化物中，可以通过 LC-MS/MS 在预期位置检测到一种二唾液酸化聚糖，然后也可以通过标准 MALDI TOF MS 检测到。计划借助凝集素分离糖肽。振动冷却 (VC) MALDI FT-MS 可能有助于检测唾液酸化程度更高、更不稳定的同系物。