STRUCTURE FUNCTION STUDIES OF OXIDOREDUCTASES AND NUCLEIC ACID BINDING PROTEINS

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。项目1：氧化还原酶：醛糖还原酶（AR）是一种NADPH依赖的氧化还原酶，催化多种醛的还原，包括葡萄糖。研究表明，通过AR催化途径增加的己糖通量是与高血糖状态（如糖尿病）相关的组织损伤和功能障碍的潜在原因之一。AR抑制剂的临床试验结果不确定，这些药物治疗糖尿病并发症的长期疗效仍有待证实。AR已与几种化合物山梨醇、非达司他、唑来司他、托来司他、山梨醇、柠檬酸盐、羧酸盐、6-磷酸葡萄糖、恶唑氨基甲酸酯、WF-3681和IDD384以一种以上的晶体形式结晶。采用基于结构的抑制剂设计方法，我们已经证明了一类新的化合物作为AR抑制剂（Acta Cryst C61: 81-o84, 2005; Biochem Pharma 70:1653-1663, 2005）。我们目前的目标是在SSRL收集x射线衍射数据，以确定这些脂基化合物与野生型和突变型AR的复杂结构。AR与脂基化合物的晶体结构将提供AR氨基酸残基与这些化合物之间的具体相互作用。相互作用的知识将有助于我们结合生物学和临床数据区分负责不同抑制特性的独特接触。项目2：核酸结合蛋白：在许多细菌中，限制性修饰系统提供了防止DNA入侵的保护。保护的效率主要取决于限制性基因与甲基转移酶基因的相对表达水平。这种调节是由一种叫做C蛋白的控制蛋白提供的。大肠杆菌BclI系统的研究表明，C.Bcll作为M.BclI表达的负调节因子，暗示在病毒感染期间防御外源DNA的作用。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Project 1: Oxidoreductase: Aldose reductase (AR) is an NADPH dependent oxidoreductase that catalyzes the reduction of a wide variety of aldehydes including glucose. It has been shown that increased flux of hexoses via the AR catalyzed pathway is one of the underlying causes of tissue injury and dysfunction associated with hyperglycemic states such as diabetes mellitus. Clinical trials with AR inhibitors have yielded uncertain results and the long-term efficacy of these drugs in treating diabetic complications remains to be demonstrated. AR has been crystallized with several compounds sorbitol, fidarestat, zopolrestat, tolrestat, sorbinil, citrate, cacodylate, glucose 6-phosphate, oxazolecarbamate, WF-3681 and IDD384 in more than one crystal form. Employing structure-based inhibitor design approach we have demonstrated a novel class of compounds as AR inhibitors (Acta Cryst C61:o81-o84, 2005; Biochem Pharma 70:1653-1663, 2005). Our current aim is to collect x-ray diffraction data at SSRL to determine the complex structures of these lipid based compounds with wild-type and mutant forms of AR. Crystal structures of AR with the lipid based compounds will provide the specific interactions between the amino acid residues of AR and these compounds. The knowledge of the interactions will help to us distinguish the unique contacts responsible for varied inhibition properties in combination with biological and clinical data.[--cr--] Project 2: Nucleic acid binding protein: Protection from DNA invasion is afforded by restriction-modification systems in many bacteria. The efficiency of protection depends crucially on the relative expression levels of restriction versus methytransferase genes. This regulation is provided by a controller protein, named C protein. Studies of the BclI system in E. coli suggests that C.Bcll functions as a negative regulator for M.BclI expression, implying a role in defense of foreign DNA during virus infection.