MICROBIAL METABOLISM OF ALIPHATIC ALKENES AND EPOXIDES

脂肪族烯烃和环氧化物的微生物代谢

基本信息

批准号：
2900825
负责人：
Scott A. ENSIGN
金额：
$ 10.02万
依托单位：
UTAH STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1995
资助国家：
美国
起止时间：
1995-04-01 至 2000-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/2900825
关键词：
alkenes computer assisted sequence analysis electron spin resonance spectroscopy enzyme induction /repression enzyme mechanism epoxides gene induction /repression genetic regulation halocarbon compound microorganism genetics microorganism metabolism molecular cloning nucleic acid sequence protein purification ultraviolet spectrometry

项目摘要

The objective of this proposal is to investigate the physiology, biochemistry, and genetics of the microbial metabolism of aliphatic alkenes, epoxides and related halogenated compounds. There is considerable concern about the biological reactivity, toxicity and carcinogenicity of alkenes and epoxides: epoxides are potent alkylating agents which covalently modify proteins and DNA, and a broad range of alkenes are readily activated to epoxides by the monooxygenase activity of cytochrome P-450 enzymes. A number of bacteria are able to grow at the expense of aliphatic alkenes and epoxides as their sole carbon and energy source, including Xanthobacter strain Py2, a soil bacterium containing an inducible ethylene- and propylene-oxidizing system which will be used for the studies described in this proposal. In this bacterium the key enzymes of alkene metabolism are alkene monooxygenase, which catalyzes the epoxidation of alkenes to their corresponding epoxides, and an epoxidase, which further consumes these epoxides in an as yet uncharacterized reaction. The specific aims of this proposal are to (1) develop in vitro assays for, purify to homogeneity, and biochemically characterize alkene monooxygenase and epoxidase; (2) investigate the mechanism(s) by which the expression and repression of alkene monooxygenase, epoxidase, and accessory proteins is regulated; (3) determine the immediate products of alkene and epoxide metabolism and study the pathway(s) by which they are further metabolized as carbon sources; (4) isolate, clone, and characterize the genes encoding alkene monooxygenase and epoxidase; and (5) further characterize the substrate ranges of alkene monooxygenase and epoxidase, with particular emphasis on aliphatic and halogenated alkenes and epoxides of concern due to their toxicity and occurrence in the environment. Understanding the mechanisms by which bacteria are able to metabolize alkenes and epoxides will be of great interest, given the mutagenic and carcinogenic potential of these compounds. The successful completion of the objectives outlined above will contribute significantly to our understanding of bacterial metabolism of xenobiotic compounds.

该提案的目的是研究生理学，脂肪族微生物代谢的生物化学和遗传学烯烃、环氧化物和相关卤代化合物。有人们对生物反应性、毒性和烯烃和环氧化物的致癌性：环氧化物具有强效烷基化作用共价修饰蛋白质和 DNA 的试剂，以及广泛的烯烃很容易被单加氧酶活性激活为环氧化物细胞色素 P-450 酶。许多细菌能够在其中生长消耗脂肪族烯烃和环氧化物作为其唯一的碳和能量来源，包括黄杆菌菌株 Py2，一种土壤细菌，含有诱导型乙烯和丙烯氧化系统，将用于本提案中描述的研究。在这种细菌中，关键酶烯烃代谢的主要成分是烯烃单加氧酶，它催化烯烃环氧化为其相应的环氧化物，以及环氧化酶，它进一步以尚未表征的方式消耗这些环氧化物反应。该提案的具体目标是（1）开发体外测定，纯化至均质，并对烯烃单加氧酶进行生化表征和环氧酶； (2) 研究表达的机制以及烯烃单加氧酶、环氧化酶和辅助蛋白的抑制受到监管； (3) 测定烯烃和环氧化物的直接产物代谢并研究它们进一步代谢的途径作为碳源； (4) 分离、克隆和表征编码基因烯烃单加氧酶和环氧化酶； (5) 进一步表征烯烃单加氧酶和环氧化酶的底物范围，特别是重点关注脂肪族和卤代烯烃以及环氧化物其毒性和在环境中的发生情况。了解细菌代谢的机制考虑到其致突变性和这些化合物的潜在致癌性。顺利完成上述目标将大大有助于我们了解外源化合物的细菌代谢。