微泡菌QZHA1褐藻胶裂解酶MAAL1的酶学性质研究          下载免费PDF全文

闫康路  邵宗泽  王万鹏  谢珍玉  周梅先 《应用海洋学学报》2024,43(2):266-275

为探究Microbulbifer sp. QZHA1褐藻胶裂解(Escherichia coli)酶MAAL1的酶学性质,将褐藻胶裂解酶基因maal1构建至pET-28a表达载体并利用大肠杆菌BL21(DE3)进行异源表达。研究发现：重组酶MAAL1与来源于Microbulbifer sp. ALW1菌株的褐藻胶裂解酶(WP＿23625014.1)同源性最高,为93.69%,且与PL7家族蛋白聚为一支;重组酶MAAL1最适温度为35℃,最适pH为7.5,在pH为5.5～10.5范围内保存24 h仍能保持60%以上的酶活力;MAAL1具备良好的耐有机溶剂特性,在测试的9种有机溶剂中,除异丙醇外,其他有机溶剂在添加量达到30%(体积分数)后,酶活力依然保持在59%以上;重组酶MAAL1最适条件下酶活力为4.3 U/mg,米氏常数(K_m)值为1.08 mg/mL,最大反应速率(V_max)为4.75 mg/(mL·min),催化常数(K_cat)值为4.52 s^-1;重组酶MAAL1对聚β-D-甘露糖醛酸(p...  相似文献   

海洋生物对二甲基硫生产的控制作用研究   总被引：1，自引：0，他引：1  

杨桂朋  厉丞烜 《中国海洋大学学报(自然科学版)》2009,39(3)

二甲基硫(DMS)是参与全球硫循环的最主要的海洋生源硫化物,对全球气候变化和环境酸化产生重要影响.海洋中DMS的产生是一个极为复杂的生物学和生态学过程,主要涉及的生物过程包括浮游植物病毒感染、浮游动物摄食和DMSP裂解酶的活动.根据海洋生物活动在二甲基硫的全球生物地球化学循环中所起着的重要作用,作者综述了国际海洋科学工作者十几年来在DMS生物生产过程研究方面的进展.  相似文献   

Lyase Activities of Heterologous CpcS and CpcT for Phycocyanin Holo-β-subunit from Arthrospira platensis in Escherichia coli     

Junjie Yi  Di Xu  Xiaonan Zang  Dingyang Yuan  Bingran Zhao  Li Tang  Yanning Tan  Xuecheng Zhang 《中国海洋大学学报(英文版)》2014,13(3):497-502

Arthrospira platensis is an economically important cyanobacterium; and it has been used widely in food and pharmaceutical industries. The phycocyanin(PC) from A. platensis is extremely valuable in medicine and molecular biology due to its antioxidation and anti-tumoring activity and applicability as fluorescence protein tag. In present study, two recombinant plasmids, one contained the phycocyanobilin(PCB)-producing genes(hox1 and pcyA) while the other contained the phycobiliprotein gene(cpcB) and the lyase gene(either cpcS/U or cpcT), were constructed and synchronically transferred into E. coli in order to test the the activities of relevant lyases for catalysing PCB addition to CpcB during synthesizing fluorescent PC holo-β-subunit(β-PC) of A. platensis. As was evidenced by the fluorescence emitted at a peak specific for PC, CpcB was successfully synthesized in E. coli, to which co-expressed PCBs attached though at a relatively low efficiency. The results showed that the attachment of PCBs to CpcB were carried out mainly by co-expressed CpcS/U but CpcB also showed some autocatalytic activity. Currently, no CpcT activity was detected in this E. coli expression system. Further studies will be conducted to improve the efficiency of fluorescent PC synthesis in E. coli.  相似文献