猪细胞色素P450氧化酶3A46的催化及调控分子机制

项目名称： 猪细胞色素P450氧化酶3A46的催化及调控分子机制

项目编号： No.31201716

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 生物科学

项目作者： 蒋珺

作者单位： 华南农业大学

项目金额： 21万元

中文摘要： 研究参与重要内源或外源化合物代谢的猪细胞色素P450氧化酶（Cytochrome P450, CYP）的功能、结构、催化机制和调控机理，不但对兽医药理与毒理学研究非常重要，对于新药研发、人类健康也同等重要。我们的前期研究结果显示CYP3A46是猪肝脏中一个重要的代谢酶，它能代谢尼福地平、T-2和HT-2毒素。因此，本项目拟以猪CYP3A46为研究对象，对其可能的关键氨基酸残基进行定点突变，确定影响其对尼福地平、T-2和HT-2毒素的特异性识别、结合、催化活性及别构作用的关键位点，并构建模型假说揭示其催化分子机制；利用荧光素酶报告基因系统、凝胶阻滞、染色质免疫沉淀等技术研究利福平、T-2和HT-2毒素调控CYP3A46表达的分子机制及其差异。本项目的研究结果将最终阐明CYP3A46的催化及调控分子机制，填补相关研究的空白，并可望为减少T-2毒素对畜禽乃至人类的危害提供新的思路。

中文关键词： 猪；CYP3A46；T-2毒素；催化机制；转录调控

英文摘要： Studying the function, structure, catalytic mechanism and regulational mechanism of a porcine CYP isoform, which is involved in the metabolism of important endogenous or exogenous compounds, is important not only for veterinary pharmacology and toxicology but also for new drug development and human health. Our previous research results indicated that porcine CYP3A46 is a critical metabolic enzyme in pig liver, which can metabolize nifedipine, T-2 toxin and HT-2 toxin. To reveal the catalytic and regulational mechanisms of CYP3A46, we will mutate and identify the key amino acid residues contributing to its specific recognition, binding, catalytic activity and allosteric effect towards nifedipne, T-2 toxin and HT-2 toxin, and then propose hypotheses to uncover its catalytic mechanism. Additionally, we will study its regulational mechanism under the treatments of rifampicin, T-2 toxin and HT-2 toxin, through luciferase reporter system, electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitaion (Chip). Our project will clarify the catalytic and regulational mechanisms of CYP3A46 and fill gaps at related research field. Furthermore, related research results will probably provide new ideas to reduce the toxicity of T-2 toxin towards livestock and humans.

英文关键词： Pig；Cytochrome P450 3A46；T-2 toxin；Catalytic mechanism；Transcriptional regulation