| 摘要: |
| 为了探究海带(Saccharina japonica)α-CA1和α-CA2是否具有催化CO2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±0.120 U/mg)几乎是rα-CA2(0.54±0.046 U/mg)的3倍,表明rα-CA1催化CO2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±0.176 U/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。 |
| 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 |
| DOI：10.11759/hykx20220105001 |
| 分类号:S968.31 |
| 基金项目:国家自然科学基金项目(41376136);国家重点研发计划项目(2018YFD0901500) |
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| Comparative analysis of enzyme activities of two recombinant a-carbonic anhydrases (a-CAs) of Saccharina japonica |
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WANG Zhen1, BI Yan-hui1, ZHOU Zhi-gang1,2
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1.Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources Conferred by Ministry of Education, Shanghai Ocean University, Shanghai 201306, China;2.International Research Center for Marine Biosciences Conferred by Ministry of Science and Technology, Shanghai 201306, China
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| Abstract: |
| In order to explore whether the two reported alpha carbonic anhydrases (a-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 CO2hydration 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 CO2 concentrating mechanism of this kelp. |
| Key words: Saccharina japonica a-carbonic anhydrase (CA) procaryotic expression hydration activity esterase activity |
