重组L-乳酸脱氢酶在大肠杆菌中的表达、纯化及活性研究  

Overexpession and Purification of Phenylactic Acid Producing. Lactate Dehydrogenase Gene (ldhL) in E. coli

作　　者：贾江花[1] 沐万孟[1] 张涛[1] 江波[1] 

机构地区：[1]江南大学食品科学与技术国家重点实验室

出　　处：《食品与发酵工业》2009年第5期22-25,共4页Food and Fermentation Industries

基　　金：国家自然科学基金重点项目(20436020)

摘　　要：乳酸脱氢酶是生物法转化苯丙酮酸为苯乳酸的一种有效的酶。实验克隆到一种新型L-乳酸脱氢酶基因ldhL,来源于Lactobacillus plantarumSK-2(植物乳杆菌SK-2),GenBank接受号为FJ392647。以pET-22b(+)为载体质粒,E.coliBL21(DE3)为宿主细胞,构建了基因重组菌,IPTG可诱导目的蛋白的过量表达;经亲和层析纯化的重组蛋白样品进行SDS-PAGE电泳分析,约在37ku处出现显著的特征蛋白条带;重组LDH的比酶活为0.06U/mg。Lactate dehydrogenase（LDH） is the main enzyme for biotransformation of phenylpruvatic acid （PPA） to phenyllactic acid（PLA） which is a novel antimicrobial compound. A gene, ldhL （GenBank FJ392647）, encoding L-LDH from Lactbacillus plantarum SK-2 was cloned and over-expressed in Escherich- ia coli. The encoded polypeptide had 310 residues. There was a 99.78% similarity to LDH from L. planta- rum WCFS1 with the exception of one amino acid. The recombinant enzyme was purified to electrophoretic homogeneity by affinity chromatography. The enzyme molecular weight was 37 ku with an activity on PPA of 0.06 U/mg after dialysis.

关 键 词：乳酸脱氢酶 苯乳酸 苯丙酮酸 基因重组 亲和层析 

分 类 号：Q814[生物学—生物工程]