![[feed]](/style/images/feed-icon-14x14.png){kind=icon}
Tools
Tools
Preview |
PDF (Original Article)
- Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
2MB |
Preview |
PDF (Supporting Information)
- Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
11MB |
| Item Type: | Article |
|---|---|
| Title: | pH-dependent protonation of surface carboxylate groups in PsbO enables local buffering and triggers structural changes |
| Creators Name: | Gerland, L. M., Friedrich, D., Hopf, L., Donovan, E., Wallmann, A., Erdmann, N., Diehl, A., Bommer, M., Buzar, K., Ibrahim, M., Schmieder, P., Dobbek, H., Zouni, A., Bondar, A.-N., Dau, H. and Oschkinat, H. |
| Abstract: | Photosystem II (PSII) catalyzes the splitting of water, releasing protons and dioxygen. Its highly conserved subunit PsbO extends from the oxygen‐evolving center (OEC) into the thylakoid lumen and stabilizes the catalytic Mn(4)CaO(5) cluster. The high degree of conservation of accessible negatively charged surface residues in PsbO suggests additional functions, as local pH buffer or by affecting the flow of protons. For this discussion, we provide an experimental basis, through the determination of pK(a) values of water‐accessible aspartate and glutamate side‐chain carboxylate groups by means of NMR. Their distribution is strikingly uneven, with high pK(a) values around 4.9 clustered on the luminal PsbO side and values below 3.5 on the side facing PSII. pH‐dependent changes in backbone chemical shifts in the area of the lumen‐exposed loops are observed, indicating conformational changes. In conclusion, we present a site‐specific analysis of carboxylate group proton affinities in PsbO, providing a basis for further understanding of proton transport in photosynthesis. |
| Keywords: | NMR Spectroscopy, Photosystem II, pH Titration, pK(a), Value, Protonation |
| Source: | ChemBioChem |
| ISSN: | 1439-4227 |
| Publisher: | Wiley-VCH |
| Volume: | 21 |
| Number: | 11 |
| Page Range: | 1597-1604 |
| Date: | 2 June 2020 |
| Official Publication: | https://doi.org/10.1002/cbic.201900739 |
| PubMed: | View item in PubMed |
Repository Staff Only: item control page
