Structure and function of protein disulfide isomerase

蛋白质二硫键异构酶的结构和功能

• 批准号: 59634953
• 负责人: Professor Dr. Hermann Schindelin
• 金额: --
• 依托单位: Rudolf-Virchow-Zentrum - Center for Integrative and Translational Bioimaging
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/59634953?language=en
• 关键词: Structure; function; protein; disulfide; isomerase

The formation of disulfide bonds in many secretory proteins represents an essential step in their folding and maturation, and protein disulfide isomerase (PDI) is the key enzyme required for disulfide bond formation. It oxidizes two cysteine residues in newly synthesized proteins to form a disufide bridge and also catalyzes the isomerization of incorrectly formed disulfide linkages in proteins containing three or more cysteine residues. Our initial crystal structure of PDI revealed that the two catalytically competent (a and a’) and two inactive (b and b’) thioredoxin-like domains are arranged in the shape of the letter “U”. The active sites in the a and a’ domains are located on opposite ends of the “U” with a large substratebinding cleft located between them, and the b and b’ domains form the base of the “U”. A subsequent lower resolution structure demonstrated large-scale conformational changes. Through a combination of biochemical, biophysical and structural studies we will study the contribution of domain motions to the catalytic activity of PDI, analyze the interaction of the enzyme with different substrates and its redox partner Ero1, structurally characterize mammalian PDI to rationalize variations of the catalytically active domains in and between species, and we will also determine structures with inhibitors to further refine the catalytic mechanism and as a starting point for rational drug design.

二硫键的形成是许多分泌性蛋白质折叠和成熟的重要步骤，而蛋白质二硫键异构酶（PDI）是二硫键形成所需的关键酶。它氧化新合成蛋白质中的两个半胱氨酸残基以形成二硫键，并且还催化含有三个或更多半胱氨酸残基的蛋白质中错误形成的二硫键的异构化。我们的PDI的初始晶体结构揭示了两个催化活性（a和a '）和两个无活性（B和b'）硫氧还蛋白样结构域以字母“U”的形状排列。a和a'结构域中的活性位点位于“U”的相对两端，在它们之间有一个大的底物结合裂缝，B和B'结构域形成“U”的碱基。随后的较低分辨率的结构表现出大规模的构象变化。通过生物化学，生物物理和结构研究的结合，我们将研究结构域运动对PDI催化活性的贡献，分析酶与不同底物及其氧化还原伴侣Ero 1的相互作用，结构表征哺乳动物PDI以合理化物种内和物种间催化活性结构域的变化，我们还将确定具有抑制剂的结构，以进一步完善催化机制，并作为合理药物设计的起点。