STRUCTURAL STUDIES OF LIPID/PROTEIN SYSTEMS

脂质/蛋白质系统的结构研究

• 批准号: 6180065
• 负责人: LEONARD J. BANASZAK
• 金额: $ 34.07万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-05-01 至 2003-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6180065
• 关键词: X ray crystallography; acyl coA dehydrogenases; apolipoproteins; binding proteins; calorimetry; chemical kinetics; conformation; crystallization; fatty acid binding protein; fatty acid transport; intermolecular interaction; ionization constant; lipid transport; microsomes; nonblood lipoprotein; protein binding; protein disulfide isomerase; protein structure; retinoid binding proteins; sterol esterase; structural biology; thermodynamics; transport proteins; triglycerides; vitellin

DESCRIPTION (Adapted from abstract): The long-term objective is to provide data on the interaction of lipids with transport proteins or enzymes. To do this, the molecular structure of lipid-containing macromolecules will be used to describes lipid-protein interactions. A nearly complete study of lipovitellin has led to similar studies of microsomal triglyceride transfer protein (MTP), which is involved in assembly of the serum lipoproteins. A major aim is to compete the crystal structure of a complex of MTP with protein disulfide isomerase. For lipovitellin, new x-ray measurements have provided preliminary evidence about the conformation of 20 bound acyl chains. The new data will be refined and an effort will be made to reconstruct the entire domain of phospholipids present in lipovitellin. Attempts to crystallize apo A1, the principal protein component of HDL will be continued. In the beta-oxidation spiral, more than one enzyme appears to be associated with each reaction. For the beta-OH to beta-ketoacyl CoA reaction, humans have two different enzymes: one for short chain L-3-hydroxyacyl CoA substrates (SCHAD) and one for long chain metabolites (LCHAD). Preliminary x-ray data have identified the coenzyme site of SCHAD. The important goal now is to characterize the molecular structure that defines the origin of fatty acid chain specificity. This will be done by x-ray analyses of SCHAD associated with appropriate substrates. In a second stage, the LCHAD segment of a multifunctional protein will be expressed in E. coli, crystallized, and the 3D structure determined by diffraction methods. In a continuation of structural studies of intracellular proteins for shuttling fatty acids and retinoids, mutagenesis, titration calorimetry, and x-ray crystallography will be used to explore ligand specificity. One approach will combine experimental determination of proton binding with electrostatic calculations of characteristic pKs.

描述(摘自摘要)：长期目标是提供数据 关于脂类与转运蛋白或酶的相互作用。要做到这点， 含脂大分子的分子结构将被用于 描述脂类与蛋白质的相互作用。卵黄蛋白脂的研究近乎完整 导致了对微粒体甘油三酯转移蛋白(MTP)的类似研究， 它参与了血清脂蛋白的组装。一个主要目标是 MTP与蛋白质二硫键形成的络合物的晶体结构竞争 异构酶。对于卵黄脂蛋白，新的x射线测量已经提供了初步的 20个结合的酰基链构象的证据。新数据将是 精炼并努力重建整个领域 卵黄素中的磷脂。试图使载脂蛋白A1结晶， 高密度脂蛋白的主要蛋白质成分将继续。 在β-氧化螺旋中，似乎有不止一种酶与之相关。 每一种反应。对于β-羟基到β-酮酰辅酶A的反应，人类有 两种不同的酶：一种用于短链L-3-羟基酰辅酶A底物 一种是长链代谢物(LCHAD)。初步的X射线数据显示 鉴定了Schad的辅酶切点。现在的重要目标是 描述定义脂肪酸起源的分子结构 链的专一性。这将通过对SCHAD的X-射线分析来完成 合适的底物。在第二阶段，LCHAD段 多功能蛋白将在大肠杆菌中表达、结晶和3D 由衍射法确定的结构。 在用于穿梭的细胞内蛋白质的结构研究的继续中 脂肪酸和类维A酸、诱变、滴定量热法和x射线 结晶学将被用来探索配基的特异性。一种方法将 质子结合与静电结合的实验测定 特征PKS的计算。