Characterization of the Phosphotransferase from <i>Bacillus subtilis</i> 1101 That Is Responsible for the Biotransformation of Zearalenone
<i>Bacillus</i> microorganisms play an important role in the zearalenone (ZEA) biotransformation process in natural environments. The phosphotransferase pathway in <i>Bacillus</i> is both widespread and relatively well conserved. However, the reaction kinetics of these phosph...
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| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-01-01
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| Series: | Toxins |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2072-6651/17/1/21 |
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| Summary: | <i>Bacillus</i> microorganisms play an important role in the zearalenone (ZEA) biotransformation process in natural environments. The phosphotransferase pathway in <i>Bacillus</i> is both widespread and relatively well conserved. However, the reaction kinetics of these phosphotransferases remain poorly understood, and their catalytic activities are suboptimal. In this study, a ZEA phosphotransferase, ZPH1101, was identified from <i>Bacillus subtilis</i> 1101 using genome sequencing. The product transformed by ZPH1101 was identified as phosphorylated ZEA (ZEA-P) through LC-TOF-MS/MS analysis. The experiments conducted on MCF-7 cells demonstrated that ZEA-P exhibited a lower level of estrogenic toxicity than ZEA. The optimal reaction conditions for ZPH1101 were determined to be 45 °C and pH 8.0. The maximum velocity (<i>V</i><sub>max</sub>), Michaelis constant (<i>K</i><sub>m</sub>), and catalytic constant (<i>k</i><sub>cat</sub>) were calculated through fitting to be 16.40 μM·s<sup>−1</sup>·mg<sup>−1</sup>, 18.18 μM, and 54.69 s<sup>−1</sup>, respectively. Furthermore, adding 1 mmol/L Fe<sup>2+</sup> or Fe<sup>3+</sup> to the reaction system increased the efficiency of ZPH1101 in converting ZEA by 100% relative to the system containing solely 1 mmol/L ATP and 1 mmol/L Mg<sup>2+</sup>, suggesting that low concentrations of Fe<sup>2+</sup> or Fe<sup>3+</sup> can improve the ZPH1101-mediated transformation of ZEA. This study contributes to the enzymatic removal of ZEA and broadens the spectrum of strain and enzyme options available to researchers for ZEA detoxification efforts. |
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| ISSN: | 2072-6651 |