Purification and Mechanism of Microcystinase MlrC for Catalyzing Linearized Cyanobacterial Hepatotoxins Using <i>Sphingopyxis</i> sp. USTB-05
Cyanobacterial hepatotoxins, including microcystins (MCs) and nodularins (NODs), are widely produced, distributed and extremely hazardous to human beings and the environment. However, the catalytic mechanism of microcystinase for biodegrading cyanobacterial hepatotoxins is not completely understood...
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2022-08-01
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author | Qianwen Zou Junhui Teng Kunyan Wang Yiming Huang Qingbei Hu Sisi Chen Qianqian Xu Haiyang Zhang Duyuan Fang Hai Yan |
author_facet | Qianwen Zou Junhui Teng Kunyan Wang Yiming Huang Qingbei Hu Sisi Chen Qianqian Xu Haiyang Zhang Duyuan Fang Hai Yan |
author_sort | Qianwen Zou |
collection | DOAJ |
description | Cyanobacterial hepatotoxins, including microcystins (MCs) and nodularins (NODs), are widely produced, distributed and extremely hazardous to human beings and the environment. However, the catalytic mechanism of microcystinase for biodegrading cyanobacterial hepatotoxins is not completely understood yet. The first microcystinase (MlrA) catalyzes the ring opening of cyclic hepatotoxins, while being further hydrolyzed by the third microcystinase (MlrC). Based on the homology modeling, we postulated that MlrC of <i>Sphingopyxis</i> sp. USTB-05 was a Zn<sup>2+</sup>-dependent metalloprotease including five active sites: Glu56, His150, Asp184, His186 and His208. Here, the active recombinant MlrC and five site-directed mutants were successfully obtained with heterologous expression and then purified for investigating the activity. The results indicated that the purified recombinant MlrC had high activity to catalyze linearized hepatotoxins. Combined with the biodegradation of linearized NOD by MlrC and its mutants, a complete enzymatic mechanism for linearized hepatotoxin biodegradation by MlrC was revealed. |
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spelling | doaj.art-998a6228325242d59b335f2ed07493912023-11-23T19:16:32ZengMDPI AGToxins2072-66512022-08-0114960210.3390/toxins14090602Purification and Mechanism of Microcystinase MlrC for Catalyzing Linearized Cyanobacterial Hepatotoxins Using <i>Sphingopyxis</i> sp. USTB-05Qianwen Zou0Junhui Teng1Kunyan Wang2Yiming Huang3Qingbei Hu4Sisi Chen5Qianqian Xu6Haiyang Zhang7Duyuan Fang8Hai Yan9School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaSchool of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaSchool of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaSchool of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaSchool of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaSchool of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaSchool of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaSchool of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaBeijing Royal School, Beijing 102209, ChinaSchool of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaCyanobacterial hepatotoxins, including microcystins (MCs) and nodularins (NODs), are widely produced, distributed and extremely hazardous to human beings and the environment. However, the catalytic mechanism of microcystinase for biodegrading cyanobacterial hepatotoxins is not completely understood yet. The first microcystinase (MlrA) catalyzes the ring opening of cyclic hepatotoxins, while being further hydrolyzed by the third microcystinase (MlrC). Based on the homology modeling, we postulated that MlrC of <i>Sphingopyxis</i> sp. USTB-05 was a Zn<sup>2+</sup>-dependent metalloprotease including five active sites: Glu56, His150, Asp184, His186 and His208. Here, the active recombinant MlrC and five site-directed mutants were successfully obtained with heterologous expression and then purified for investigating the activity. The results indicated that the purified recombinant MlrC had high activity to catalyze linearized hepatotoxins. Combined with the biodegradation of linearized NOD by MlrC and its mutants, a complete enzymatic mechanism for linearized hepatotoxin biodegradation by MlrC was revealed.https://www.mdpi.com/2072-6651/14/9/602cyanobacterial hepatotoxinsmicrocystinase (MlrC)active sitemechanism |
spellingShingle | Qianwen Zou Junhui Teng Kunyan Wang Yiming Huang Qingbei Hu Sisi Chen Qianqian Xu Haiyang Zhang Duyuan Fang Hai Yan Purification and Mechanism of Microcystinase MlrC for Catalyzing Linearized Cyanobacterial Hepatotoxins Using <i>Sphingopyxis</i> sp. USTB-05 Toxins cyanobacterial hepatotoxins microcystinase (MlrC) active site mechanism |
title | Purification and Mechanism of Microcystinase MlrC for Catalyzing Linearized Cyanobacterial Hepatotoxins Using <i>Sphingopyxis</i> sp. USTB-05 |
title_full | Purification and Mechanism of Microcystinase MlrC for Catalyzing Linearized Cyanobacterial Hepatotoxins Using <i>Sphingopyxis</i> sp. USTB-05 |
title_fullStr | Purification and Mechanism of Microcystinase MlrC for Catalyzing Linearized Cyanobacterial Hepatotoxins Using <i>Sphingopyxis</i> sp. USTB-05 |
title_full_unstemmed | Purification and Mechanism of Microcystinase MlrC for Catalyzing Linearized Cyanobacterial Hepatotoxins Using <i>Sphingopyxis</i> sp. USTB-05 |
title_short | Purification and Mechanism of Microcystinase MlrC for Catalyzing Linearized Cyanobacterial Hepatotoxins Using <i>Sphingopyxis</i> sp. USTB-05 |
title_sort | purification and mechanism of microcystinase mlrc for catalyzing linearized cyanobacterial hepatotoxins using i sphingopyxis i sp ustb 05 |
topic | cyanobacterial hepatotoxins microcystinase (MlrC) active site mechanism |
url | https://www.mdpi.com/2072-6651/14/9/602 |
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