The Structure of Bilirubin Oxidase from <i>Bacillus pumilus</i> Reveals a Unique Disulfide Bond for Site-Specific Direct Electron Transfer
Efficient oxygen-reducing biocatalysts are essential for the development of biofuel cells or photo-bioelectrochemical applications. Bilirubin oxidase (BOD) is a promising biocatalyst for oxygen reduction processes at neutral pH and low overpotentials. BOD has been extensively investigated over the l...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-04-01
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| Series: | Biosensors |
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| Online Access: | https://www.mdpi.com/2079-6374/12/5/258 |
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| author | Shalev Gihaz Nidaa Shrara Herzallh Yifat Cohen Oren Bachar Ayelet Fishman Omer Yehezkeli |
| author_facet | Shalev Gihaz Nidaa Shrara Herzallh Yifat Cohen Oren Bachar Ayelet Fishman Omer Yehezkeli |
| author_sort | Shalev Gihaz |
| collection | DOAJ |
| description | Efficient oxygen-reducing biocatalysts are essential for the development of biofuel cells or photo-bioelectrochemical applications. Bilirubin oxidase (BOD) is a promising biocatalyst for oxygen reduction processes at neutral pH and low overpotentials. BOD has been extensively investigated over the last few decades. While the enzyme’s internal electron transfer process and methods to establish electrical communication with electrodes have been elucidated, a crystal structure of BOD from bacterial origin has never been determined. Here we present the first crystal structure of BOD from <i>Bacillus pumilus</i> (<i>Bp</i>BOD) at 3.5 Å resolution. Overall, <i>Bp</i>BOD shows high homology with the fungal enzymes; however, it holds a unique surface-exposed disulfide bond between Cys229 and Cys322 residues. We present methodologies to orient the T1 site towards the electrode by coupling the reduced disulfide bond with maleimide moiety on the electrodes. The developed configurations were further investigated and revealed improved direct electron transfer rates with the electrodes. The work presented here may contribute to the construction of rationally designed bioanodes or biocathode configurations that are based on redox-active enzymes. |
| first_indexed | 2024-03-10T03:15:20Z |
| format | Article |
| id | doaj.art-39c56f4757c144f5850d8e77dd32aaa9 |
| institution | Directory Open Access Journal |
| issn | 2079-6374 |
| language | English |
| last_indexed | 2024-03-10T03:15:20Z |
| publishDate | 2022-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Biosensors |
| spelling | doaj.art-39c56f4757c144f5850d8e77dd32aaa92023-11-23T10:14:53ZengMDPI AGBiosensors2079-63742022-04-0112525810.3390/bios12050258The Structure of Bilirubin Oxidase from <i>Bacillus pumilus</i> Reveals a Unique Disulfide Bond for Site-Specific Direct Electron TransferShalev Gihaz0Nidaa Shrara Herzallh1Yifat Cohen2Oren Bachar3Ayelet Fishman4Omer Yehezkeli5Department of Biotechnology and Food Engineering, Technion—Israel Institute of Technology, Haifa 3200003, IsraelDepartment of Biotechnology and Food Engineering, Technion—Israel Institute of Technology, Haifa 3200003, IsraelDepartment of Biotechnology and Food Engineering, Technion—Israel Institute of Technology, Haifa 3200003, IsraelDepartment of Biotechnology and Food Engineering, Technion—Israel Institute of Technology, Haifa 3200003, IsraelDepartment of Biotechnology and Food Engineering, Technion—Israel Institute of Technology, Haifa 3200003, IsraelDepartment of Biotechnology and Food Engineering, Technion—Israel Institute of Technology, Haifa 3200003, IsraelEfficient oxygen-reducing biocatalysts are essential for the development of biofuel cells or photo-bioelectrochemical applications. Bilirubin oxidase (BOD) is a promising biocatalyst for oxygen reduction processes at neutral pH and low overpotentials. BOD has been extensively investigated over the last few decades. While the enzyme’s internal electron transfer process and methods to establish electrical communication with electrodes have been elucidated, a crystal structure of BOD from bacterial origin has never been determined. Here we present the first crystal structure of BOD from <i>Bacillus pumilus</i> (<i>Bp</i>BOD) at 3.5 Å resolution. Overall, <i>Bp</i>BOD shows high homology with the fungal enzymes; however, it holds a unique surface-exposed disulfide bond between Cys229 and Cys322 residues. We present methodologies to orient the T1 site towards the electrode by coupling the reduced disulfide bond with maleimide moiety on the electrodes. The developed configurations were further investigated and revealed improved direct electron transfer rates with the electrodes. The work presented here may contribute to the construction of rationally designed bioanodes or biocathode configurations that are based on redox-active enzymes.https://www.mdpi.com/2079-6374/12/5/258Bilirubin oxidase<i>Bacillus pumilus</i>bioelectrocatalysisX-ray crystallographyelectron transfersite-specific immobilization |
| spellingShingle | Shalev Gihaz Nidaa Shrara Herzallh Yifat Cohen Oren Bachar Ayelet Fishman Omer Yehezkeli The Structure of Bilirubin Oxidase from <i>Bacillus pumilus</i> Reveals a Unique Disulfide Bond for Site-Specific Direct Electron Transfer Biosensors Bilirubin oxidase <i>Bacillus pumilus</i> bioelectrocatalysis X-ray crystallography electron transfer site-specific immobilization |
| title | The Structure of Bilirubin Oxidase from <i>Bacillus pumilus</i> Reveals a Unique Disulfide Bond for Site-Specific Direct Electron Transfer |
| title_full | The Structure of Bilirubin Oxidase from <i>Bacillus pumilus</i> Reveals a Unique Disulfide Bond for Site-Specific Direct Electron Transfer |
| title_fullStr | The Structure of Bilirubin Oxidase from <i>Bacillus pumilus</i> Reveals a Unique Disulfide Bond for Site-Specific Direct Electron Transfer |
| title_full_unstemmed | The Structure of Bilirubin Oxidase from <i>Bacillus pumilus</i> Reveals a Unique Disulfide Bond for Site-Specific Direct Electron Transfer |
| title_short | The Structure of Bilirubin Oxidase from <i>Bacillus pumilus</i> Reveals a Unique Disulfide Bond for Site-Specific Direct Electron Transfer |
| title_sort | structure of bilirubin oxidase from i bacillus pumilus i reveals a unique disulfide bond for site specific direct electron transfer |
| topic | Bilirubin oxidase <i>Bacillus pumilus</i> bioelectrocatalysis X-ray crystallography electron transfer site-specific immobilization |
| url | https://www.mdpi.com/2079-6374/12/5/258 |
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