Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.
FEMS Microbiol Lett. 2011 Nov;324(2):98-105. doi: 10.1111/j.1574-6968.2011.02387.x. Epub 2011 Sep 15.
Streptomyces transglutaminase (TGase) is secreted as a zymogen (pro-TGase) in liquid cultures and is then processed by the removal of its N-terminal region, resulting in active TGase. To date, there is no report describing TGase (or pro-TGase) secretion in Escherichia coli. In this study, the pro-TGase from Streptomyces hygroscopicus was efficiently secreted by E. coli BL21(DE3) using the TGase signal peptide or the pelB signal peptide. The secreted pro-TGase was efficiently transformed into active TGase by adding dispase to the culture supernatant of the recombinant strains. Mutational analysis showed that deletion of the first six amino acids of the N-terminal of the pro-region reduced the secretion of pro-TGase, and removal of the next 10 amino acids resulted in the formation of insoluble pro-TGase. These results suggest that the pro-region of TGase is essential for its efficient secretion and solubility in E. coli.
链霉菌转谷氨酰胺酶（TGase）在液体培养中作为酶原（原 TGase）分泌，然后通过去除其 N 端区域进行加工，从而产生有活性的 TGase。迄今为止，尚无关于大肠杆菌中 TGase（或原 TGase）分泌的报道。在这项研究中，使用 TGase 信号肽或 pelB 信号肽，来自吸水链霉菌的原 TGase 可被大肠杆菌 BL21(DE3)有效分泌。通过向重组菌株的培养上清液中添加Dispase，可将分泌的原 TGase有效地转化为有活性的 TGase。突变分析表明，原 N 端前 6 个氨基酸的缺失会降低原 TGase 的分泌，而去除接下来的 10 个氨基酸会导致原 TGase 形成不溶性。这些结果表明，TGase 的原区域对于其在大肠杆菌中的有效分泌和可溶性是必需的。
