Tracing the Pathways of Waters and Protons in Photosystem II and Cytochrome c Oxidase
Photosystem II (PSII) uses water as the terminal electron donor, producing oxygen in the Mn<sub>4</sub>CaO<sub>5</sub> oxygen evolving complex (OEC), while cytochrome c oxidase (CcO) reduces O<sub>2</sub> to water in its heme⁻Cu binuclear center (BNC). E...
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| Format: | Article |
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MDPI AG
2019-01-01
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| Series: | Inorganics |
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| Online Access: | https://www.mdpi.com/2304-6740/7/2/14 |
| _version_ | 1798043722949066752 |
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| author | Divya Kaur Xiuhong Cai Umesh Khaniya Yingying Zhang Junjun Mao Manoj Mandal Marilyn R. Gunner |
| author_facet | Divya Kaur Xiuhong Cai Umesh Khaniya Yingying Zhang Junjun Mao Manoj Mandal Marilyn R. Gunner |
| author_sort | Divya Kaur |
| collection | DOAJ |
| description | Photosystem II (PSII) uses water as the terminal electron donor, producing oxygen in the Mn<sub>4</sub>CaO<sub>5</sub> oxygen evolving complex (OEC), while cytochrome c oxidase (CcO) reduces O<sub>2</sub> to water in its heme⁻Cu binuclear center (BNC). Each protein is oriented in the membrane to add to the proton gradient. The OEC, which releases protons, is located near the P-side (positive, at low-pH) of the membrane. In contrast, the BNC is in the middle of CcO, so the protons needed for O<sub>2</sub> reduction must be transferred from the N-side (negative, at high pH). In addition, CcO pumps protons from N- to P-side, coupled to the O<sub>2</sub> reduction chemistry, to store additional energy. Thus, proton transfers are directly coupled to the OEC and BNC redox chemistry, as well as needed for CcO proton pumping. The simulations that study the changes in proton affinity of the redox active sites and the surrounding protein at different states of the reaction cycle, as well as the changes in hydration that modulate proton transfer paths, are described. |
| first_indexed | 2024-04-11T22:53:05Z |
| format | Article |
| id | doaj.art-d840a219f8b64dffab28c62fe7b0006a |
| institution | Directory Open Access Journal |
| issn | 2304-6740 |
| language | English |
| last_indexed | 2024-04-11T22:53:05Z |
| publishDate | 2019-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Inorganics |
| spelling | doaj.art-d840a219f8b64dffab28c62fe7b0006a2022-12-22T03:58:32ZengMDPI AGInorganics2304-67402019-01-01721410.3390/inorganics7020014inorganics7020014Tracing the Pathways of Waters and Protons in Photosystem II and Cytochrome c OxidaseDivya Kaur0Xiuhong Cai1Umesh Khaniya2Yingying Zhang3Junjun Mao4Manoj Mandal5Marilyn R. Gunner6Department of Physics, City College of New York, New York, NY 10031, USADepartment of Physics, City College of New York, New York, NY 10031, USADepartment of Physics, City College of New York, New York, NY 10031, USADepartment of Physics, City College of New York, New York, NY 10031, USADepartment of Physics, City College of New York, New York, NY 10031, USADepartment of Physics, City College of New York, New York, NY 10031, USADepartment of Physics, City College of New York, New York, NY 10031, USAPhotosystem II (PSII) uses water as the terminal electron donor, producing oxygen in the Mn<sub>4</sub>CaO<sub>5</sub> oxygen evolving complex (OEC), while cytochrome c oxidase (CcO) reduces O<sub>2</sub> to water in its heme⁻Cu binuclear center (BNC). Each protein is oriented in the membrane to add to the proton gradient. The OEC, which releases protons, is located near the P-side (positive, at low-pH) of the membrane. In contrast, the BNC is in the middle of CcO, so the protons needed for O<sub>2</sub> reduction must be transferred from the N-side (negative, at high pH). In addition, CcO pumps protons from N- to P-side, coupled to the O<sub>2</sub> reduction chemistry, to store additional energy. Thus, proton transfers are directly coupled to the OEC and BNC redox chemistry, as well as needed for CcO proton pumping. The simulations that study the changes in proton affinity of the redox active sites and the surrounding protein at different states of the reaction cycle, as well as the changes in hydration that modulate proton transfer paths, are described.https://www.mdpi.com/2304-6740/7/2/14proton pumpingnetwork analysisproton affinityproton coupled electron transfer |
| spellingShingle | Divya Kaur Xiuhong Cai Umesh Khaniya Yingying Zhang Junjun Mao Manoj Mandal Marilyn R. Gunner Tracing the Pathways of Waters and Protons in Photosystem II and Cytochrome c Oxidase Inorganics proton pumping network analysis proton affinity proton coupled electron transfer |
| title | Tracing the Pathways of Waters and Protons in Photosystem II and Cytochrome c Oxidase |
| title_full | Tracing the Pathways of Waters and Protons in Photosystem II and Cytochrome c Oxidase |
| title_fullStr | Tracing the Pathways of Waters and Protons in Photosystem II and Cytochrome c Oxidase |
| title_full_unstemmed | Tracing the Pathways of Waters and Protons in Photosystem II and Cytochrome c Oxidase |
| title_short | Tracing the Pathways of Waters and Protons in Photosystem II and Cytochrome c Oxidase |
| title_sort | tracing the pathways of waters and protons in photosystem ii and cytochrome c oxidase |
| topic | proton pumping network analysis proton affinity proton coupled electron transfer |
| url | https://www.mdpi.com/2304-6740/7/2/14 |
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