小麦蛋白质二硫键异构酶（wPDI）由4个硫氧还蛋白结构域a-b-b’-a’和C-末端c尾组成。为考察wPDI各结构域对其活性的影响，本研究通过亚克隆表达了八个不同结构域组成的wPDI截短蛋白，表达产物经分离纯化后进行了酶学性质研究和蛋白质电泳分析。结果表明，设计的八个wPDI截短蛋白在大肠杆菌BL21（DE3）中得到了表达，金属螯合亲和层析和分子排阻层析后获得了纯度较高的wPDI截短蛋白；活性测定结果表明，wPDI的所由结构域对其二硫键氧化还原活性和分子伴侣活性都有贡献，c尾不影响其异构活性，但提供了分子伴侣活性的关键氨基酸结合位点；对截短蛋白A和A’的电泳分析发现，wPDI的a结构域活性位点主要以氧化态为主，而a’主要以还原态为主。研究结果为深入理解wPDI的功能性质奠定了基础。

The wheat protein disulfide isomerase (wPDI) contains four thioredoxin domains a-b-b'-a' and a C-ter- minal tail c.In order to investigate the effect of each domain of wPDI on its properties,eight truncated proteins of wPDI containing different domain combinations were constructed by subcloning.The target proteins were prepared after expression and purification,and then their enzymatic properties and products of protein electrophoresis were determined and analyzed.The results indicate that eight truncated proteins of wPDI are expressed in E.coli BL21,and that,after the metal chelate affinity chromatography and the size exclusion chromatography,the truncated pro- teins of wPDI of high purity are obtained.The results from activities assay indicate that all domains of wPDI contrib- ute to its disulfide bond oxidoreductase activity and molecular chaperone activity,and that,the truncation of tail c has no effect on its isomerase activity but retains the critical amino acid binding site for the molecular chaperone ac- tivity.Moreover,the electrophoretic analysis of the truanted proteins A and A' demonstrates that the active-site cys- teines in domain a are primarily in an oxidized state while those of domain a' are primarily in a reduced state.Therefore,these results lay a foundation for deeply understanding the function and property of wPDI.