STRUCTURAL STUDIES OF LIPID/PROTEIN SYSTEMS

脂质/蛋白质系统的结构研究

• 批准号: 2903157
• 负责人: LEONARD J. BANASZAK
• 金额: $ 35.65万
• 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/2903157
• 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（改编自摘要）：长期目标是提供数据 脂质与转运蛋白或酶的相互作用。为此， 含脂质大分子的分子结构将用于 描述脂质-蛋白质相互作用。卵黄蛋白的近乎完整的研究 引发了微粒体甘油三酯转移蛋白（MTP）的类似研究， 它参与血清脂蛋白的组装。一个主要目标是 竞争 MTP 与蛋白质二硫化物复合物的晶体结构 异构酶。对于卵黄蛋白，新的 X 射线测量提供了初步的结果 有关 20 个结合酰基链构象的证据。新数据将是 细化并努力重建整个领域 磷脂存在于卵黄蛋白中。尝试使apo A1结晶， HDL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 随着每个反应。对于 β-OH 到 β-酮脂酰 CoA 的反应，人类有 两种不同的酶：一种用于短链 L-3-羟酰基 CoA 底物 （SCHAD）和一种用于长链代谢物（LCHAD）。初步 X 射线数据有 鉴定出 SCHAD 的辅酶位点。现在重要的目标是 表征定义脂肪酸起源的分子结构 链的特异性。这将通过 SCHAD 的 X 射线分析来完成 合适的基材。在第二阶段，LCHAD 部分 多功能蛋白将在大肠杆菌中表达、结晶，并进行 3D 分析 结构由衍射法测定。 细胞内穿梭蛋白结构的继续研究 脂肪酸和类维生素A、诱变、滴定量热法和 X 射线 晶体学将用于探索配体特异性。一种方法将 将质子结合与静电的实验测定相结合 特征 pK 的计算。