Enzymatic Biodegradation of Chlorooxides

氯氧化物的酶促生物降解

• 批准号: 7153545
• 负责人: Jennifer L DuBois
• 金额: $ 7.28万
• 依托单位: UNIVERSITY OF NOTRE DAME
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-12-06 至 2008-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7153545
• 关键词: Agriculture; Anemia; Benzene; Biochemical; Biochemistry; Biocide; Biodegradation; Biological; Biological Assay; Biomedical Engineering; Bioremediations; California; Candidate Disease Gene; Carcinogens; Child; Chlorates; Chronic; Dental Pulp; Depth; Development; Drug Metabolic Detoxication; Elements; Environment; Environmental Health; Environmental Monitoring; Environmental Pollution; Enzymes; Excision; Fresh Water; Future; Genes; Genome; Goals; Health; Health Hazards; Herbicides; Human; Human Activities; Hydrocarbons; Industry; Infant; Ions; Location; Maintenance; Methods; Microbe; Military Personnel; Modeling; Motivation; N-terminal; NBL1 gene; Nature; Open Reading Frames; Organism; Oxidants; Oxidoreductase; Paper; Pathway interactions; Perchlorates; Play; Post-Translational Protein Processing; Process; Property; Protein Biochemistry; Protein Engineering; Proteins; Respiration; Risk; Roentgen Rays; Role; Salts; Site; Solubility; Staging; Standards of Weights and Measures; Structural Protein; Structure; System; Testing; Toxic effect; United States Environmental Protection Agency; Universities; Water; Water Supply; Work; anthropogenesis; base; chlorate reductase; chlorite; drinking water; enzyme activity; enzyme pathway; fresh water environment; genome sequencing; microbial; microorganism; mutant; nervous system disorder; respiratory; response; sensor

DESCRIPTION (provided by applicant): The chlorooxide (ClOx-) ions are anthropogenic biocides, bleaches, and oxidants that, because of their high solubility and ubiquitous use by agriculture, industry, and the military, have become major contaminants of drinking water and fresh water environments. The various chlorooxides are both suspected and documented health hazards. The following proposal will determine the feasibility of in-depth studies of microbe-based ClOx- detoxification at the protein/enzyme level. The U.S. EPA has included chlorite (CIO2-) on its list of Primary Drinking Water Standards, with a legally mandated upper limit of 0.8 mg/L in drinking water. Health risks associated with chronic CIO2- exposure include anemia and nervous system disorders in children and infants. After its recent identification as a well water contaminant, perchlorate (CIO4-) was added to the EPA's Contaminant Candidate List. Its full health effects are currently under study by the EPA and by others. In response to an influx of chlorooxides, nature has evolved mechanisms to detoxify and even exploit them. Microorganisms that anaerobically respire chlorooxides, including CIO4-, CIO3-, and CIO2-, have been isolated over the last decade. Traditional means of removing small ions from water are expensive or nonspecific, so bioremediation of chlorooxides is an emerging bioengineering goal. Dechloromonas aromatica, the only (ClOx-)-respiring microbe with a sequenced genome, is the obvious choice for biochemical study (J.D. Coates, University of California, Berkeley). Moreover, Dechloromonas is unique among strains in pure culture, in that it oxidizes intransigent hydrocarbons including benzene, a major environmental contaminant and a potent human carcinogen. We seek [1] to isolate, partially sequence, and identify the genes encoding (ClOx-)-metabolizing activities in D. aromatica; [2] to obtain sufficient quantities of pure enzymes for mechanistic and X-ray structural studies from the host and heterologous expression systems; and [3] to partially characterize the endogenous and expressed enzymes. These objectives set the stage for future mechanistic, spectroscopic, structural, and protein-engineering studies of these components of the (ClOx-) detoxification pathway. This work will be part of a more global effort aimed at developing bioremediation systems, and/or enzyme-based sensors for environmental monitoring.

说明(申请人提供)：氯氧化物(ClOx-)离子是人为杀生剂、漂白剂和氧化剂，由于其高溶解度和广泛用于农业、工业和军事，已成为饮用水和淡水环境的主要污染物。各种氯氧化物都是可疑的和有据可查的健康危害。以下建议将确定在蛋白质/酶水平上深入研究基于微生物的ClOx解毒的可行性。美国环保局已将亚氯酸盐(ClO2-)列入其主要饮用水标准名单，法律规定饮用水中的上限为0.8毫克/L。与慢性接触CIO2有关的健康风险包括儿童和婴儿的贫血和神经系统疾病。在最近被确认为井水污染物后，高氯酸盐(CIO4-)被添加到美国环保局的污染物候选名单中。其对健康的全面影响目前正在由美国环保局和其他机构进行研究。为了应对氯氧化物的涌入，大自然进化出了解毒甚至利用它们的机制。在过去的十年里，已经分离出了厌氧呼吸氯氧化物的微生物，包括ClO_4-、CIO_3~-和CIO_2~-。传统的去除水中小离子的方法价格昂贵或非特异性，因此氯氧化物的生物修复是一个新兴的生物工程目标。芳香地氯单胞菌是唯一一种具有测序基因组的(ClOx-)呼吸微生物，是生化研究的明显选择(J.D.Coates，加州大学伯克利分校)。此外，在纯培养的菌株中，十氯单胞菌是独一无二的，因为它能氧化包括苯在内的不妥协的碳氢化合物，苯是一种主要的环境污染物，也是一种强有力的人类致癌物质。我们寻求[1]分离、部分测序和鉴定编码芳香毒蛾(ClOx-)代谢活性的基因；[2]从宿主和异源表达系统中获得足够数量的纯酶，用于机械和X射线结构研究；以及[3]部分表征内源性和表达的酶。这些目标为未来对(ClOx-)解毒途径的这些组成部分的机械学、光谱、结构和蛋白质工程研究奠定了基础。这项工作将是旨在开发生物修复系统和/或用于环境监测的酶传感器的更全球性努力的一部分。