茂原链轮丝菌转谷氨酰胺酶基因在大肠杆菌中高效表达

利用PCR方法从茂原链轮丝菌(Streptoverticillium mobaraense)基因组DNA扩增出微生物转谷氨酰胺酶(Microbial Transglutaminase,MTG)的基因片段，并构建表达质粒Pet-MTG。后者在大肠杆菌（Rosetta DE3）中得到高效表达，但表达的MTG存在于包涵体中。经洗涤、变性和复性，并以强阳离子交换层析纯化，获得了SDS-PAGE纯的MTG，并具有与天然酶几乎相同的比活性。此项工作为工业化生产MTG打下了基础。

High Expression of Mirobial Transglutaminase Gene from Streptoverticillium Mobaraense in Escherichia coli

The microbial transglutamunase (MTG) gene was amplified from the genomic DNA of Streptoverticillium mobaraensea by using PCR and inserted into pET vector to construct the expression plasmid called pET_MTG. The pET_MTG was transfected into E.coli(Rosetta DE3) and the MTG protein was found to be highly expressed as inclusion bodies. The inclusion bodies were isolated and subjected to denaturation and re_naturation, followed by strong cation ion_exchange chromatography to purify the expressed MTG. The specific activity of purified MTG was close to that of native MTG. Taken together, this study might provide a base for the industrial production of microbial transglutaminase.