Mechanisms of Protein Protection by Desiccation-tolerance Molecules

通过这个奖项，化学部门的生命过程化学项目资助了北卡罗来纳大学教堂山分校的Gary J. Pielak博士，以研究大小耐干燥分子使用的蛋白质保护机制。被选择在干燥环境中生存的生物体是通过制造保护性分子来做到这一点的，但保护的机制大多是未知的。从实践的角度来看，了解脱水保护将改善生物制造工艺和生物基产品，如生物药物和工业酶。这些研究将为研究生和本科生提供蛋白质化学和物理生物化学方面的专业培训，这是基础和工业研究的有用技能。PI还将与卡罗莱纳盟约（Carolina Covenant）合作，培养对化学研究感兴趣的学生。卡罗莱纳盟约是一个帮助低收入的北卡罗来纳大学学生无债务毕业的项目。提出的解释干燥保护的四个主要观点——保水、玻璃化、水替代和分子屏蔽假说——将通过结合蛋白质工程、核磁共振光谱、傅立叶变换红外光谱和流变学来检验。最常见的天然保护性小分子是不还原性双糖海藻糖，但也有几类保护性无序蛋白质。研究最充分的成员是晚期胚胎发生丰富（LEA）蛋白，它在植物中发现，但也在动物中发现。最近发现的一类保护蛋白-细胞质丰富的热可溶性（CAHS）蛋白-是缓步动物所特有的。CAHS蛋白之所以引人注目，不仅是因为它们能保护其他蛋白质和酶，还因为它们能形成保护凝胶。该项目将比较和对比每种类型的保护性分子，以更好地了解它们的结构如何有助于生物体在脱水条件下的生存。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With this award, the Chemistry of Life Processes Program in the Chemistry Division is funding Dr. Gary J. Pielak from the University of North Carolina at Chapel Hill to investigate mechanisms of protein protection used by large and small desiccation tolerance molecules. Organisms selected to survive desiccation do so by making protective molecules, but the mechanisms of protection are mostly unknown. From a practical perspective, understanding dehydration protection will improve biomanufacturing processes and bio-based products, such as biologic drugs and industrial enzymes. These studies will provide graduate and undergraduate students with specialized training in protein chemistry and physical biochemistry, which are useful skills for basic and industrial research. The PI will also work with the Carolina Covenant, a program that helps low-income UNC students graduate debt-free, to train students interested in chemistry research.The four main ideas proposed to explain desiccation protection — water retention, vitrification, water replacement and molecular shield hypotheses — will be tested by using a combination of protein engineering, nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy and rheometry. The most common natural protective small molecule is the nonreducing disaccharide, trehalose, but there are also several classes of protective disordered proteins. The most well-studied members are the Late Embryogenesis Abundant (LEA) proteins, which were discovered in plants but are also found in animals. The most recently discovered class of protective proteins — Cytosolic Abundant Heat Soluble (CAHS) proteins — are unique to tardigrades. CAHS proteins are remarkable not only because they protect other proteins and enzymes but also because they form protective gels. This project will compare and contrast each of these types of protective molecules to better understand how their structures contribute to the survival of organisms under dehydrating conditions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.