目的构建重组金属硫蛋白2A(MT-2A)原核表达质粒,并在大肠埃希菌BL21(DE3)中表达,为进一步研究MT-2A奠定基础。方法从人骨骼肌细胞cDNA文库中PCR扩增MT-2A基因DNA序列,构建重组表达质粒MT2A-pET32a,PCR与DNA测序法鉴定插入序列;重组细菌用IPTG诱导表达,His-bind亲和层析柱纯化MT-2A蛋白,Western blotting鉴定蛋白特性。结果扩增获得的MT-2A基因片段长186bp,DNA测序证实MT2A-pET32a重组质粒构建正确;表达的融合蛋白相对分子质量约为29×103,Western blotting证实为目的蛋白。结论成功构建了重组原核表达质粒MT2A-pET32a,在大肠埃希菌内诱导表达并纯化获得MT-2A。 Objective To construct prokaryotic expression plasmid of recombinant metallothionein 2A (MT-2A) and express it in Escherichia coli BL21 (DE3), so as to lay the foundation for the further study of MT-2A. Methods The MT2A gene DNA sequence was amplified by PCR from the human skeletal muscle cDNA library and the recombinant plasmid MT2A-pET32a was constructed. The inserted sequence was identified by PCR and DNA sequencing. Recombinant bacteria were induced by IPTG and His-bind affinity chromatography MT-2A protein was purified by column and identified by Western blotting. Results The amplified MT-2A gene fragment was 186 bp long. DNA sequencing confirmed that the constructed recombinant plasmid of MT2A-pET32a was constructed correctly. The relative molecular mass of the expressed fusion protein was about 29 × 103, which was verified by Western blotting. Conclusion The recombinant prokaryotic expression plasmid MT2A-pET32a was successfully constructed and induced in Escherichia coli and purified to obtain MT-2A.