CRYSTALLOGRAPHIC STUDIES OF PROTEIN STRUCTURE/FUNCTION

本应用程序的长期目标是了解结构 酶的催化能力的起源，以了解酶的功能， 蛋白质构象变化和原子波动的重要性， 描述蛋白质中辐射损伤的结构后果 和核酸，并应用蛋白质晶体学技术 和计算机建模，以提供详细的分子图像， 细菌趋化性感觉系统 这些目标中的第一个应该是 为酶活性的合理设计提供重要的基础信息 药物和了解几种疾病，如肺气肿， 涉及酶缺乏或酶是关键的有毒物质 实质内容。 关于蛋白质结构变化的知识 既响应于特异性配体的结合， 在常温下可用的动能将是互补的 静态蛋白质的结构图。 辐射损伤 生物体是一个重要的健康考虑因素， 受损分子结构的细节常常是不确定的。 受损蛋白质和核酸结构的表征 酸应该有助于设计防辐射化合物， 可能对那些认为辐射是食物的人有用， 保护措施 细菌趋化系统是一个很有潜力的 人类感觉系统的模型，如嗅觉，味觉和 可以触摸。 我们的具体目标包括确定 B的三维结构嗜热脂肪菌丙氨酸消旋酶. 单晶X射线法分辨率2.5A以上 衍射，确定该复合物的结构， 具有底物D-或L-丙氨酸和具有膦酸酯缓慢结合的酶 抑制剂;结晶和晶体结构测定 来自鼠伤寒沙门氏菌趋化系统的甲基酯酶; 以高分辨率进行确定和细化（即，约1.5A）的 弹性蛋白酶与其酰基酶中底物复合物的晶体结构 中间体形式、酶产物形式和米氏复合物 低温X射线酰化前的酶与底物 结晶学;抹香鲸的结构特征 50%辐射损伤时的高铁肌红蛋白;几种DNA样 寡核苷酸双链体分子在相似的剂量，和完整的 两种蛋白质压力和温度依赖性的测定 结构.

The long-term goals of this application are to understand the structural origins of the catalytic power of enzymes, to understand the functional importance of protein conformational changes and atomic fluctuations, to characterize the structural consequences of radiation damage in proteins and nucleic acids, and to apply the techniques of protein crystallography and computer modelling to provide a detailed molecular picture of the bacterial chemotactic sensory system. The first of these aims should provide basic information important to rational design of enzyme-active drugs and to an understanding of several diseases, such as emphysema, that involve enzyme deficiency or where an enzyme is the critical toxic substance. Knowledge of the changes in structure that proteins undergo both in response to the binding of specific ligands and as a consequence of the kinetic energy available at ordinary temperatures will be complementary to the structural picture of the static protein. Radiation damage to living organisms is a significant health consideration, and the precise details of the structures of the damaged molecules are often uncertain. Characterization of the structures of the damaged proteins and nucleic acids should aid in the design of radiation-protecting compounds, and also may be of use for people who consider the use of radiation as a food preservative measure. The bacterial chemotactic system is a good potential model for the sensory systems in human beings, such as smell, taste and possibly touch. Our specific aims include the determination of the three-dimensional structure of B. stearothermophilus alanine racemase at 2.5A resolution or higher by the method of single-crystal X-ray diffraction, the determination of the structures of the complex of this enzyme with substrate D- or L- alanine and with a phosphonate slow-binding inhibitor; the crystallization and crystal structure determination of the methyl esterase from the chemotactic system of Salmonella typhimurium; the determination and refinement at high resolution (i.e., about 1.5A) of the crystal structures of elastase complexed with substrate in its acyl-enzyme intermediate form, the enzyme-product form, and the Michaelis complex of enzyme with substrate prior to acylation by low-temperature X-ray crystallography; characterization of the structure of sperm-whale met-myoglobin at 50% radiation damage; characterization of several DNA-like oligonucleotide duplex molecules at similar doses, and the complete determination of the pressure and temperature dependence of two protein structures.