Structure-Function Studies of Lipid Binding Proteins

脂质结合蛋白的结构功能研究

• 批准号: 0131326
• 负责人: David Bernlohr
• 金额: $ 36.76万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2005-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0131326&HistoricalAwards=false
• 关键词: Structure; Function; Studies; Lipid; Binding

The prevalence of water-insoluble compounds in biological systems has driven the evolutionary development of families of hydrophobic ligand carrier proteins. Just as there are carrier proteins that function to solubilize and deliver hydrophobic molecules in the circulatory system (e.g., lipoprotein particles, albumin, etc.), there exists a homologous family of proteins that are found intracellularly. These proteins, which have been termed the fatty acid binding proteins (FABPs), are responsible for the solubilization and delivery of hydrophobic ligands within a cell. The FABPs bind most avidly to fatty acids and retinoids. The signature feature of all FABPs is a Beta-barrel fold forming an internal, water-filled cavity that serves as the ligand-binding domain. A 1:1 non-covalent complex is typically formed between the protein and the ligand and once inside, the ligand is sequestered from the external milieu. The adipocyte FABP (FABP4) has been studied in detail as a model for structure-function relationships of the fatty acid binding proteins. The investigators hypothesize that FABP4 functions to donate insoluble long chain fatty acids to acyl CoA synthetase producing a soluble lipid (acyl CoA). To test this hypothesis, they will: (I) evaluate the effect of FABP4 on the catalytic activity and ligand binding properties of very long chain acyl CoA synthetase and (ii) examine the physical interaction of FABP4 with the acyl CoA synthetase using microcalorimetry and map the interaction site(s).

水不溶性化合物在生物系统中的普遍存在推动了疏水配体载体蛋白家族的进化发展。正如有载体蛋白在循环系统中起溶解和递送疏水分子的作用（例如，脂蛋白颗粒、白蛋白等），在细胞内发现有一个同源蛋白质家族。这些蛋白质被称为脂肪酸结合蛋白（FABPs），负责细胞内疏水配体的溶解和递送。FABPs与脂肪酸和类维生素A结合最活跃。所有FABP的标志性特征是形成内部充水腔的β桶折叠，该腔充当配体结合结构域。蛋白质和配体之间通常形成1：1的非共价复合物，一旦进入，配体就与外部环境隔离。 脂肪细胞FABP（FABP 4）作为脂肪酸结合蛋白结构-功能关系的模型已被详细研究。研究人员假设FABP 4的功能是将不溶性长链脂肪酸提供给酰基辅酶A合成酶，产生可溶性脂质（酰基辅酶A）。为了验证这一假设，他们将：（I）评估FABP 4对极长链酰基CoA合成酶的催化活性和配体结合特性的影响，（ii）使用微量热法检查FABP 4与酰基CoA合成酶的物理相互作用，并绘制相互作用位点。