Flexibility vs Thermal Stability in Rubredoxin Proteins

红氧还蛋白蛋白质的灵活性与热稳定性

• 批准号: 6421759
• 负责人: Griselda Hernandez
• 金额: $ 24.45万
• 依托单位: WADSWORTH CENTER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-01-01 至 2005-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6421759
• 关键词: Archaea; Clostridium; acidity /alkalinity; amides; chemical kinetics; chemical reaction; computer simulation; conformation; cryoscience; intermolecular interaction; microorganism culture; microorganism genetics; molecular dynamics; molecular site; nuclear magnetic resonance spectroscopy; protein denaturation; protein purification; protein structure function; rubredoxins; site directed mutagenesis; species difference; temperature; thermodynamics; thermostability

DESCRIPTION (provided by applicant): The recent characterizations of organisms that live at temperatures above 90oC, so-called hyperthermophiles, have provided an ever-increasing set of proteins which are far more thermostable than the homologous proteins obtained from organisms living at typical ambient temperatures (i.e. mesophiles). With the massive genomic sequence information now available, enzyme-based industrial processes and pharmacological therapies utilizing bioactive proteins are positioned for greatly expanded development. Physical studies of the hyperthermophile proteins are stimulated by the expectation that detailed comparison to the homologous mesophile proteins will provide insight into how increased thermal stability can be systematically engineered into proteins. Unfortunately, the physical studies to date have made it clear that the structural bases of thermostabilization are subtle in detail. Furthermore, hyperthermophile enzymes are uniformly found to be far less active than their mesophile counterparts when tested under the same ambient conditions. Both thermal stability and reduced catalytic activities of hyperthermophile proteins are commonly ascribed in increased conformational rigidity. Understanding the relationship between flexibility in the native state and global stability requires determination of the timeframe and magnitude of motions which differ between mesophile and hyperthermophile protein as well as an approach to systematic alteration of these effects. The rubredoxins from Pyrococcus furiosus and Clostridium pasteurianum offer a good model system in which the amide exchange for all backbone amides can be monitored over a wide range of pH, temperature and denaturant in a fashion which distinguishes conformational transitions both faster and slower than 1 sec(-1). Dioxygen paramagnetic relaxation measurements provide a time averaged measure of the spatial distribution of O2 throughout the protein structure. Furthermore, the spatial distribution of the sequence variations between the two rubredoxins provides a systematic path of interconversion which preserves native-like interactions.

描述（由申请人提供）：有机体的最新特征 生活在90oC以上的温度下，所谓的高温噬菌体具有 提供了一套不断增加的蛋白质，这些蛋白质更热稳定 比从典型环境中的生物获得的同源蛋白 温度（即中介）。使用大量的基因组序列信息 现在可用，基于酶的工业过程和药理疗法 利用生物活性蛋白的定位是大大扩展的发展。 高疗法蛋白的物理研究被刺激 期望与同源性中间蛋白的详细比较将 提供有关如何系统地增加热稳定性的洞察力 设计成蛋白质。不幸的是，迄今为止的体育研究已经进行 它清楚地表明，恒温的结构基础在细节上是微妙的。 此外，高疗酶均匀地发现活性远不那么活跃 在同一环境下进行测试时，比其嗜噬菌对应物 状况。热稳定性和降低的催化活性 高疗蛋白通常归因于增加的构象 刚性。 了解本地国家的灵活性与 全球稳定性需要确定时间范围和幅度 在嗜熟和高疗蛋白以及同时不同的运动 这些影响的系统改变的方法。来自 Furiosus和梭子座的遗urianum在 可以在宽阔的范围内监视所有偏根酰胺的酰胺交换 pH，温度和变性剂的范围以区分的方式 构象过渡的速度比1秒（-1）更快且较慢。二恶英 顺磁性放松测量提供了时间平均 O2在整个蛋白质结构中的空间分布。此外， 两种Rubredoxin之间序列变化的空间分布 提供了一个系统的互换路径，可保留类似天然 互动。