摘要
β-丙氨酸作为一种重要的平台化合物,是合成含氮化合物的前体。相较于化学合成法,人们更倾向于利用L-天冬氨酸-α脱羧酶(ADC)环保地制备β-丙氨酸。由于细菌来源的ADC存在严重的机理性底物失活,限制了其在工业上的应用。实验在大肠杆菌中表达了3种古细菌来源的ADC,纯化和测定了其对于L-天冬氨酸的脱羧活性。考察了来源于詹氏甲烷球菌的重组酶(ADCM.j)的酶学性质和辅酶磷酸吡哆醛的稳定性,进行了酶转化实验。重组酶ADCM.j的比酶活为6.87U/mg,最适温度和pH分别为80℃和8.0,具有很强的热稳定性,适合用于工业生产。这类磷酸吡哆醛依赖型ADC,酶催化中没有基于机理的底物失活作用,但其辅酶的稳定性和循环利用是其酶催化中的主要限制因素。
β-alanine serves as an important platform chemical for the production of nitrogen containing chemicals.Production ofβ-alanine by L-aspartateα-decarboxylase(ADC)was preferred in the recent years with the advantage of environmentally friendliness.However,the substrate inactivation of bacterial ADC limited its application on an industrial scale.Here,three pyridoxal phosphate-dependent ADCs were expressed in Escherichia coli and purified to investigate its catalytic performance.ADC from Methanocaldococcus jannaschii(ADC M.j)showed high specific activity of 6.87 U/mgtowards L-aspartate,anditsoptimal temperature and pH were 80℃and 8.0,respectively.As ADC M.j exhibitedhigh thermal stability and was not inhibited byhigh concentration of substrate,it is a promisingbiocatalyst for industrial production ofβ-alanine.
作者
莫芹
李由然
石贵阳
MO Qin;LI Youran;SHI Guiyang(The Key Laboratory of Industrial Biotechnology,Ministry of Education,National Engineering Laboratory for Cereal Fermentation Technology,School of Biotechnology,Jiangnan University,Wuxi 214122,China)
出处
《发酵科技通讯》
CAS
2019年第2期63-68,78,共7页
Bulletin of Fermentation Science and Technology
基金
国家自然科学基金资助项目(31401674)
江苏省科技项目(BE2016628)
作者简介
莫芹(1990-),女,安徽巢湖人,博士生,研究方向为生物催化,E-mail:mq926@sina.cn;通信作者:石贵阳教授,E-mail:gyshi@jiangnan.edu.cn。
