2个重组海带α-碳酸酐酶(CA)的酶活性比较研究  

Comparative analysis of enzyme activities of two recombinant α-carbonic anhydrases(α-CAs)of Saccharina japonica

作　　者：王震 毕燕会[1] 周志刚[1,2] WANG Zhen;BI Yan-hui;ZHOU Zhi-gang(Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources Conferred by Ministry of Education,Shanghai Ocean University,Shanghai 201306,China;International Research Center for Marine Biosciences Conferred by Ministry of Science and Technology,Shanghai 201306,China)

机构地区：[1]上海海洋大学水产遗传资源开发利用教育部重点实验室,上海201306 [2]上海海洋大学国家海洋生物科学国际联合研究中心,上海201306

出　　处：《海洋科学》2022年第7期61-69,共9页Marine Sciences

基　　金：国家自然科学基金项目(41376136);国家重点研发计划项目(2018YFD0901500)。

摘　　要：为了探究海带(Saccharina japonica)α-CA1和α-CA2是否具有催化CO_(2)的可逆水合反应和酯酶活性,作者通过原核表达得到这两种α-CA的可溶性的异源重组蛋白。分别用电极法和酯酶活性检测法来检测重组α-CA1(rα-CA1)和rα-CA2的水合酶活性和酯酶活性,结果发现,rα-CA1的水合酶活性(1.52±0.120U/mg)几乎是rα-CA2(0.54±0.046U/mg)的3倍,表明rα-CA1催化CO_(2)的水合能力明显大于rα-CA2。而两者的酯酶活性并没有显著的差别(rα-CA1比活力:0.697±0.176U/g,rα-CA2比活力:0.743±0.129 U/g),说明催化乙酸对硝基苯酯(p-NPA)生成对硝基苯酚(p-NP)的能力是没有显著差别的。实验结果证实这2个α-CA为功能蛋白,可能参与海带无机碳吸收和储存过程,因此,本研究为海带无机碳吸收和储存机制的解析提供了生物化学依据。In order to explore whether the two reported alpha carbonic anhydrases(α-CA1 and α-CA2) of Saccharina japonica were active, the soluble recombinant proteins of them expressed in Escherichia coli were obtained.After purification, the hydratase activity as well as esterase activity of the two recombinant α-CAs(rα-CA1 and rα-CA2) were detected. The results showed that the hydratase activity of rα-CA1(1.52±0.120 U/mg) was almost three times higher than that of rα-CA2(0.54 ± 0.046 U/mg), indicating that rα-CA1exibited much higher catalytic activity for CO_(2) hydration than rα-CA2. There was no significant difference between the esterase activities of rα-CA1(0.697±0.176 U/g) and rα-CA2(0.743±0.129 U/g), indicating that there was no significant difference between the two rα-CAs in catalyzing the conversion of p-nitrophenyl acetate(p-NPA) to p-nitrophenol(p-NP). The results confirmed that these two α-CAs were functional proteins, and might participate in the process of inorganic carbon absorption and storage in S. japonica. This study provided biochemical proofs for the CO_(2) concentrating mechanism of this kelp.

关 键 词：海带(Saccharina japonica) α-碳酸酐酶(CA) 原核表达 水合酶活性 酯酶活性 

分 类 号：S968.31[农业科学—水产养殖]