重组酪氨酸脱羧酶酶学性质  

Enzymatic Properties of Recombinant Tyrosine Decarboxylase

作　　者：王鹏[1] 高晗[1] 刘茜[1] 刘均忠[1] 焦庆才[1] 

机构地区：[1]南京大学生命科学学院医药生物技术国家重点实验室,江苏南京210093

出　　处：《精细化工》2014年第7期844-847,861,共5页Fine Chemicals

基　　金：国家技术创新基金(02CJ-13-01-16)~~

摘　　要：酪氨酸脱羧酶能以L-酪氨酸为底物脱羧生成酪胺。该文利用pET28a为载体在宿主细胞E.coli BL21(DE3)中重组表达了短乳杆菌来源的酪氨酸脱羧酶,并研究了其酶学性质,考察了起始pH、温度、辅酶、底物浓度等因素对酶活的影响。结果表明,酪氨酸脱羧酶重组表达成功,酶促反应工艺为:在1 mL转化液中含有0.18 g L-酪氨酸,0.02 g湿菌体,0.2 mol/L的醋酸缓冲溶液和0.2 mmol/L的5'-磷酸吡哆醛,40℃,pH=5.5,反应7 h,L-酪氨酸的摩尔转化率达到99%。酪氨酸脱羧酶酶活为29.2 U/g,Km值和Vmax为0.71 mmol/L和9.31mol/(L·min·g)。Tyrosine decarboxylase （TDC） is an enzyme that catalyzes the decarboxylation of L-tyrosine to produce tyramine and CO2. In this study, the vector pET-28a was used to recombinant expressed the tdc gene from Lactobacillus brevis in Escherichia coli BL21 （DE3）. Several influencing factors of the enzyme reaction, such as pH, temperature, coenzyme, concentration of substrate, were all investigated. The results indicated that the recombinant tyrosine decarboxylase was successfully expressed and the reaction was optimal at pH 5.5 and 40℃, 0.02 g/mL cells, 0.2 M acetic acid buffer solution （pH 5.5）, 0.2mM 5-pyridoxal phosphate and 0.18 g/mL L-tyrosine. After 7 hours, the mole conversion rate of L-tyrosine was up to 99%. TDC’s enzyme activity is 29.2 U/g. The Km and Vmax values of TDC were 0.71mM and 9.31mol/L·min·g.

关 键 词：酪氨酸脱羧酶 酪胺 重组表达 短乳杆菌 L-酪氨酸 生物工程 

分 类 号：TQ464.8[化学工程—制药化工]