信号肽对浸麻类芽孢杆菌α-环糊精葡萄糖基转移酶在大肠杆菌中胞外表达的影响  

Effects of signal peptides on extracellular expression of Peanibacillus macerans a-cyclodextrin glycosyltransferase in recombinant Escherichia coli

作　　者：李彬[1,2] 吴敬[1,2] 陈坚[1,2] 

机构地区：[1]食品科学与技术国家重点实验室,江南大学无锡214122 [2]工业生物技术教育部重点实验室江南大学生物工程学院,无锡214122

出　　处：《工业微生物》2011年第3期54-59,共6页Industrial Microbiology

基　　金：国家杰出青年基金(20625619);食品科学与技术国家重点实验室科研基金(SKLF-MB-200802);973项目(2007CB 714036)

摘　　要：为了筛选得到利于浸麻类芽孢杆菌Paenibacillus macerans α-环糊精葡萄糖基转移酶(α-CGT酶)分泌表达的信号肽,提高α-CGT酶的分泌表达量,本研究考察了大肠杆菌中外源蛋白分泌表达常用的OmpA、PelB、OmpT和Endoxylanase四个信号肽对重组α-CGT酶在大肠杆菌中胞外表达的影响。在相同的发酵条件下,OmpA信号肽介导的分泌效果最好,发酵72 h,胞外酶活达到了32 U/mL,分别是PelB、OmpT介导效率的2.4倍和4.3倍。Endoxylanase信号肽介导的分泌效果相对较差,在胞外只能检测到很低的α-CGT酶活性,大量α-CGT酶以不可溶性的包涵体形式存在。OmpA信号肽能够有效地介导Paenibacillus macerans α-CGT酶在重组大肠杆菌中的分泌表达。In order to enhance the secretion efficiency of Paenibacillus macerans a-cyclodextrin glycosyltransferase （α-CGTase） in recombinant Escherichia coli, signal peptide optimization was carried out in this study. Signal peptides including OmpA, PelB, OmpT and Endoxylanase were obtained by routine PCR and successive PCR, respectively. Each signal peptide was fused to the N-terminal of the mature α-CGTase and expressed in E. coli BL21 （DE3）. The α-CGTase secretion efficiency mediated by different signal peptide was investigated. The results showed that OmpA was the optimal signal peptide among all the signal peptides under the same culture conditions. After 72 h of cultivation, the extracellular a-CGTase activity could reach 32 U/mL, which was 2.4-fold and 4.3-fold that of the PelB and OmpT signal peptide, respectively. However, the secretion efficiency of Endoxylanasc was the lowest, the detectable α-CGTasc activity was quite low and a large amount of α-CGTase existed in the form of inclusion bodies. OmpA signal peptide could effectively mediate secretory expression of P. macerans a-CGTase in recombinant E. coli.

关 键 词：PAENIBACILLUS macerans α-CGT酶 胞外表达 信号肽 大肠杆菌 

分 类 号：TQ925[轻工技术与工程—发酵工程] Q93[生物学—微生物学]