Biochemistry of 2,4,5-trichlorophenoxyacetic acid degradation

虽然多卤芳香族化合物是主要的环境污染物，但人们对这些化合物的生物降解或解毒作用所涉及的酶知之甚少。我们建议利用洋葱假单胞菌AC1100对2,4,5-三氯苯氧乙酸（2,4,5- t）的降解作为多代芳香族化合物生物降解的模型。我们建议鉴定、纯化和表征参与2,4,5- t降解的酶。其中一种酶纯化后，将确定部分氨基酸序列。最后，利用该酶的氨基酸序列数据构建DNA探针克隆该蛋白的结构基因，并对其进行鉴定。我们的工作结果和Chakrabarty小组关于2,4,5- t降解的额外遗传信息将共同为我们理解多卤化芳香族化合物的微生物降解做出重要贡献。多卤芳香族化合物是主要的环境污染物；然而，人们对微生物降解这类化合物的生物化学机制知之甚少。为了利用生物学方法从我们的环境中去除这些化合物，有必要了解这些化合物的微生物降解的生物化学。我们提出以洋葱假单胞菌降解2,4,5-三氯苯氧乙酸（2,4,5- t）为模型体系，研究微生物降解多卤芳香族化合物的生物化学过程。我们将鉴定和分离参与2,4,5- t降解的酶，并克隆相应的编码酶的基因。本研究结果将为微生物降解多卤芳香族化合物提供基础信息。

Although polyhalogenated aromatic compounds are major environmental pollutants, little is known about the enzymes involved in the biodegradation or detoxification of these compounds. We propose to use the degradation of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) by Pseudomonas cepacia AC1100 as a model for the biodegradation of polyhalogenated aromatic compounds. We propose to identify, purify, and characterize enzymes involved in 2,4,5-T degradation. After one of the enzymes is purified, a partial amino acid sequence will be determined. Finally, the structural gene for the protein will be cloned using DNA probes constructed with amino acid sequence data about the enzyme, and characterized. The results from our work and additional genetic information about 2,4,5-T degradation from Chakrabarty's group will together form an important contribution to our understanding about microbial degradation of polyhalogenated aromatic compounds. %%% Polyhalogenated aromatic compounds are major environmental pollutants; however, little is known about the biochemistry of microbial degradation of such compounds. In order to use biological approaches to remove these compounds from our environment, it is necessary to understand the biochemistry of microbial degradation of these compounds. We proposed to use the degradation of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) by Pseudomonas cepacia as a model system to study the biochemistry of microbial degradation of polyhalogenated aromatic compounds. We will identify and isolate enzymes involved in 2,4,5-T degradation and clone the corresponding genes encoding the enzymes. The results from this work will provide fundamental information on microbial degradation of polyhalogenated aromatic compounds.