Radiation and Dehydration Resistance of Proteins

这项研究将确定单个蛋白质对辐射和脱水的抗性，以了解这些性质是如何在分子水平上进化的，并为设计抗辐射和脱水的蛋白质提供长期指导。辐射和脱水都是破坏生物系统的力量。它们相互关联，因为它们都会诱导产生自由基，而自由基是一种极具破坏性的化学物种。了解蛋白质如何进化以抵抗自由基损伤，有助于从根本上了解蛋白质的性质和功能，并对食品生产、生物工程、生物修复和绿色化学产生潜在的长期影响。这项研究的开展将导致对本科生和研究生以及博士后研究人员进行广泛的生物物理技术和定量分析方法的培训。该项目还包括开发新的科学推广和公共参与活动，包括基于教育的表演和面向普通观众的演示，旨在极端环境条件下交流生物化学科学。该项目特别研究了一套来自耐辐射球菌的DNA结合蛋白，并将其与来自大肠杆菌的同源蛋白进行了直接比较。耐辐射D.Radiodurans是地球上最耐辐射的生物之一，它能承受的辐射剂量是杀死人类或大肠杆菌的2000倍。通过直接检测这种抗辐射生物体中受辐射的分离蛋白的功能和稳定性，以及来自辐射敏感生物体的同等同源蛋白，该项目将回答这样一个问题：固有的辐射抗性是否是一种可进化的蛋白质属性，就像一些蛋白质进化为耐热、耐酸或耐盐一样。配对的蛋白质将在不断增加的辐射、紫外线和脱水下进行检测，以确定它们对DNA结合亲和力、蛋白质折叠和稳定性、酶活性以及抗氧化剂亲和力的不同影响。因为这个项目检查蛋白质的功能和稳定性，它不是简单地问辐射诱导的自由基对某些蛋白质的损害是否比其他蛋白质更少，它还问一些蛋白质的主要生理活动(即重要的功能部分)是否比其他种类的蛋白质更不容易受到辐射损伤，以及这种差异是如何产生的。

This research will determine the resistance of individual proteins to radiation and dehydration, in order to understand how these properties evolve at the molecular level, and to provide long-range guidance for designing radiation and dehydration resistance into proteins. Radiation and dehydration are both forces that damage biological systems. They are related to each other because both induce the production of free radicals, which are extremely destructive chemical species. Understanding how proteins may have evolved to resist free radical damage adds to the fundamental understanding of the spectrum of protein properties and capabilities, and has potential long-range impacts for food production, bioengineering, bioremediation, and green chemistry. Conduct of this research will result in the training of undergraduate and graduate students, as well as postdoctoral researchers, in a broad array of biophysical techniques and quantitative analytical methods. This project also includes development of novel science outreach and public engagement activities, including educational based performances and presentations for general audiences that are designed to communicate the science of biochemistry under extreme environmental conditions.This project specifically examines a suite of DNA binding proteins from the bacterium Deinococcus radiodurans in direct comparison with the homologous proteins from Escherichia coli. D. radiodurans is one of the most radiation resistant organisms on Earth, surviving radiation doses 2,000 times greater than those that would kill humans or E. coli. By directly examining the function and stability of the irradiated isolated proteins from this radiation resistant organism alongside the equivalent, homologous proteins from a radiation sensitive organism, the project will answer the question of whether intrinsic radiation resistance is an evolvable protein property in the same way that some proteins have evolved to be heat resistant, acid resistant, or salt resistant. The paired proteins will be examined under increasing exposure to radiation, UV light, and dehydration for differential effects on their DNA binding affinity, protein folding and stability, enzymatic activity, and affinity for antioxidants. Because this project examines protein function and stability, it does not simply ask if radiation induced free radicals damage some proteins less frequently than others, it asks if the primary physiological activities (i.e. the important functional parts) of some species of proteins are less susceptible to radiation damage than others, and how that difference originates.