Biological activity of nitrosubstituted compounds in complex mixtures

复杂混合物中硝基取代化合物的生物活性

• 批准号: 138802-2007
• 负责人: Lambert, Iain
• 金额: $ 2.19万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=363568
• 关键词: Biological; activity; nitrosubstituted; compounds; complex

Nitroaromatic, nitroheterocyclic and nitropolyaromatic compounds are examples of nitrosubstituted compounds (NSCs) that are important genotoxic components of complex matrices such as contaminated soil.  Our work over the next five years will examine the genomics of the microbial communities in contaminated soils that degrade NSCs, and will characterize the enzymes responsible for biotransformation of NSCs.1) CHARACTERIZATION OF NITROREDUCTASES.  Nitroreductses (NRs) are a group of enzymes that initiate the degradation of NSCs in bacteria.  They are important not only because of their role in biodegradation but also because the intermediates of metabolism are capable of interacting with biological macromolecules, and are responsible for the observed genotoxic and antimicrobial activity of NSCs.  Our studies will characterize NRs from a range of bacteria in order to  more completely understand a) the structural properties of NRs that are important for substrate specificity; and b) the relationships between NRs from different phylogenetic groups.2) GENOMICS OF CONTAMINATED SOILS.  Our objective in this part of the project will be to identify soil bacteria that contribute to NSC transformation, and also to identify novel pathways that may play a role in NSC transformation.  Since only a small proportion of the microbial population (~1%) is culturable by standard methods, we will focus on the soil metagenome that represents the DNA content of all microbes in the soil.  Microbial diversity of contaminated soils will be determined by molecular methods and this information will help us design PCR primers for the isolation of genes encoding NRs.  In addition we will attempt to identify novel genes associated with NSC degradation using a substrate induced gene expression screen (SIGEX), which is designed to isolate elements that are unregulated by specific NSC compounds or mixtures.

硝基芳香族、硝基杂环和硝基多芳香族化合物是硝基取代化合物（NSCs）的例子，它们是复杂基质（如受污染的土壤）的重要遗传毒性成分。在接下来的五年里，我们的工作将研究污染土壤中降解NSCs的微生物群落的基因组学，并将表征负责NSCs生物转化的酶。1)硝基还原酶的表征。硝基还原酶（Nitroreductses, NRs）是一组启动细菌中NSCs降解的酶。它们的重要性不仅在于它们在生物降解中的作用，还在于代谢的中间体能够与生物大分子相互作用，并负责观察到的NSCs的遗传毒性和抗菌活性。我们的研究将从一系列细菌中表征NRs，以便更全面地了解a) NRs的结构特性，这对底物特异性很重要；b)不同系统发育类群NRs之间的关系。2)污染土壤基因组学。我们在这部分项目中的目标是确定有助于NSC转化的土壤细菌，并确定可能在NSC转化中发挥作用的新途径。由于只有一小部分微生物群体（~1%）可以通过标准方法培养，我们将重点关注土壤宏基因组，它代表了土壤中所有微生物的DNA含量。污染土壤的微生物多样性将通过分子方法确定，这些信息将有助于我们设计PCR引物分离编码rna的基因。此外，我们将尝试使用底物诱导基因表达筛选（SIGEX）来鉴定与NSC降解相关的新基因，该筛选旨在分离不受特定NSC化合物或混合物调节的元素。