硫矿硫化叶菌麦芽寡糖基海藻糖合成酶基因的克隆与表达  

Cloning and expression of maltooligosyl trehalose synthase gene from Sulfolobus solfataricus in E.coli

作　　者：陈晓斌[1] 林建平[1] 金志华[1] 岑沛霖[1] 

机构地区：[1]浙江大学生物工程研究所,浙江杭州310027

出　　处：《化工学报》2006年第10期2393-2396,共4页CIESC Journal

摘　　要：引言海藻糖（α-D-葡糖基-[1,1]-α-D葡糖苷）是一种广泛存在于低等植物、藻类、细菌、真菌、酵母、昆虫等的非还原性二糖.在自然界中,海藻糖既是一种贮藏性糖类,又是应激代谢的重要产物,具有保护生物细胞和生物活性物质在脱水、干旱、高温、冷冻、高渗透压及有毒试剂等不良环境条件下活性免遭破坏的功能.The gene of maltooligosyl trehalose synthase （MTSase） from Sulfolobus solfataricus ATCC 35092 was amplified by using polymerase chain reaction （PCR）. The expression plasmids, pTrc99a- MTSase and pET-28a （＋）-MTSase, were constructed by inserting the DNA fragments into E. coli expression vectors, pTrc99a and pET-28a（＋） . These two plasmids were separately transformed into E. coli BL21（DE3）, JM109（DE3） and BL21-Codonplus （DE3）-RIL, and the highest specific activity of MTSase was obtained in BL21 （DE3）/pTrc99a system, which was 31.3 U·（g wet cell）^-1. To increase the expression level, the rare codons in the 5＇-and 3＇-end of the gene were substituted with E. coli preferred ones, and the present termination codon, UAG, was substituted with efficient translational termination sequence UAAU. By these modifications in the DNA sequence of MTSase gene, the specific activity of MTSase in E. coli cell was doubled.

关 键 词：麦芽寡糖基海藻糖合成酶 海藻糖 淀粉 稀有密码子 

分 类 号：Q78[生物学—分子生物学]