大肠杆菌表达系统被广泛用于重组蛋白的表达，但存在着外源蛋白容易形成包涵体、活性表达不理想、缺少蛋白活性表达动力学研究等问题，限制了大肠杆菌表达系统在酶制剂等行业的应用。本课题根据启动子对基因转录与蛋白活性表达有重要影响的理论基础，采用启动子工程的方法，对启动子进行随机突变改造并筛选得到不同转录强度的启动子用于特定酶蛋白的表达，通过分析基因转录水平与活性表达蛋白及包涵体之间的定量关系进行大肠杆菌中蛋白活性表达动力学的研究，并进一步探讨该动力学模型在摇瓶水平及发酵罐规模等不同实验尺度下的适用性。在此模型指导下，选择合适的组成型表达启动子对1-2种具有重要应用价值的酶蛋白在大肠杆菌中实现高效活性表达。本研究可以为在大肠杆菌活性表达蛋白的研究中选择适宜的启动子提供理论依据，有效解决大肠杆菌表达蛋白中的包涵体问题，提高活性蛋白表达的效率，推动大肠杆菌表达系统在酶制剂和蛋白药物的工业中更广泛的应用。

The prokaryotic host, Escherichia coli, is considered a very successful system for heterogeneous proteins expression. However, there are still a lot of problems to be solved for this system to be extensively applied in the field of industrial enzymes, such as problems of inclusion body, low activity expression for some genes, and the limitation of knowledge about dynamics of soluble expression of heterogeneous proteins in E.coli. In this proposal, a random mutagenesis method based on promoter engineering strategy is designed to obtain a series of promoters with different transcriptional strength. These promoters will be used for certain heterogeneous proteins expression in E.coli, and a model of protein active expression dynamics describing the relationship between gene transcription level and enzymatic activity and inclusion body content will be constructed. Furthermore, the applicability and flexibility of this model will be tested on the scale of shaking flask and bioreactor, respectively. Some constitutive expression promotors are planed to be used to overexpress one or two industrially potential enzymes cost-effectively with the help of the promoter engineering strategy. The results obtained in this work are critical for better understanding the relationship between transcription, translation and folding of heterogeneous proteins expressed in E.coli, and could be a guideline for selection of proper promoters for the soluble expression of heterogeneous proteins in E.coli, and may impel a more extensive and successful application of the prokaryotic expression system of E.coli in the industry of enzymes and proteic pharmaceuticals.