信号肽对酮古龙酸菌山梨糖脱氢酶表达的影响  

Impact of the Signal Peptide of L -Sorbose Dehydrogenase of Ketogulonigenium vulgare on its Expression in Escherichia coli

作　　者：韦泓丽[1,2] 熊向华[1] 汪建华[1] 游松[2] 张惟材[1] 

机构地区：[1]军事医学科学院生物工程研究所,北京100071 [2]沈阳药科大学,辽宁沈阳110016

出　　处：《生物技术通讯》2010年第5期623-627,共5页Letters in Biotechnology

摘　　要：目的:在大肠杆菌中表达山梨糖脱氢酶(SDH),通过比较携带及不携带自身信号肽时SDH功能的差异,研究信号肽的作用。方法:通过PCR从酮古龙酸菌SCB329基因组中扩增带有自身信号序列和不带自身信号序列的sdh基因序列,连接至载体pET22b,在大肠杆菌中表达;利用载体的周质信号肽将缺少自身信号肽的SDH在大肠杆菌周质中表达,考察并比较这些表达情况的异同。结果:各种方式下表达的SDH都有活性,并能在体外体系中实现产酸;同时,在酶的前端带上自身信号肽或载体信号肽的情况下,在添加人工电子受体后能够实现活菌体内产酸。结论:山梨糖脱氢酶前端有一段与蛋白的周质定位相关的信号肽,去除该信号肽后酶的表达量有所增强,但在一定情况下影响了SDH的体内产酸作用。Objective： To investigate the impact of the signal peptide of L-sorbose dehydrogenase（SDH） on the founction of the enzyme by comparation of the differences between the enzyme expressed with or without its own signal peptide in Escherichia coli.Methods： Target genes with or without their own signal sequences were generated by PCR from chromatosome of Ketogulonigenium vulgare.The genes were introduced by the expression vector,pET22b,into E.coli BL21（DE3） and expressed as periplasmic or plasmic proteins.The differences between the both strains were compared.Results： No matter the protein was expressed with the periplasm peptide of the vector or its own signal peptide,the enzyme showed the function in producing in 2-keto-L-gulonic acid in vito with precence of PMS,an artificial electron acceptor.Conclusion： The expression of SDH without the peptide increased at some extence,but cannot produce 2-keto-L-gulonic acid in vivo.The peptide is possibly a signal peptide facilitating the location of the enzyme into periplasm.

关 键 词：山梨糖脱氢酶 大肠杆菌 表达 信号肽 

分 类 号：Q78[生物学—分子生物学]