Please use this identifier to cite or link to this item:
http://hdl.handle.net/2445/204051
Title: | The Protein Matrix of Plastocyanin Supports Long-Distance Charge Transport with Photosystem I and the Copper Ion Regulates Its Spatial Span and Conductance |
Author: | López Ortiz, Manuel Zamora, Ricardo A. Giannotti, Marina Ines Gorostiza Langa, Pablo Ignacio |
Keywords: | Proteïnes Transport d'electrons Proteins Electron transport |
Issue Date: | 5-Oct-2023 |
Publisher: | American Chemichal Association |
Abstract: | Charge exchange is the fundamental process that sustains cellular respiration and photosynthesis by shuttling electrons in a cascade of electron transfer (ET) steps between redox cofactors. While intraprotein charge exchange is well characterized in protein complexes bearing multiple redox sites, interprotein processes are less understood due to the lack of suitable experimental approaches and the dynamic nature of the interactions. Proteins constrained between electrodes are known to support electron transport (ETp) through the protein matrix even without redox cofactors, as the charges housed by the redox sites in ET are furnished by the electrodes. However, it is unknown whether protein ETp mechanisms apply to the interprotein medium present under physiological conditions. We study interprotein charge exchange between plant photosystem I (PSI) and its soluble redox partner plastocyanin (Pc) and address the role of the Pc copper center. Using electrochemical scanning tunneling spectroscopy (ECSTS) current-distance and blinking measurements, we quantify the spatial span of charge exchange between individual Pc/PSI pairs and ETp through transient Pc/PSI complexes. Pc devoid of the redox center (Pcapo) can exchange charge with PSI at longer distances than with the copper ion (Pcholo). Conductance bursts associated with Pcapo/PSI complex formation are higher than in Pcholo/PSI. Thus, copper ions are not required for long-distance Pc/PSI ETp but regulate its spatial span and conductance. Our results suggest that the redox center that carries the charge in Pc is not necessary to exchange it in interprotein ET through the aqueous solution and question the canonical view of tight complex binding between redox protein partners. |
Note: | Versió postprint del document publicat a: https://doi.org/10.1021/acsnano.3c06390 |
It is part of: | Acs Nano, 2023, vol. 17, num 20, p. 20334-20344 |
URI: | http://hdl.handle.net/2445/204051 |
Related resource: | https://doi.org/10.1021/acsnano.3c06390 |
ISSN: | 1936-086X |
Appears in Collections: | Articles publicats en revistes (Institut de Bioenginyeria de Catalunya (IBEC)) |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
2023_ACSNano_TheProtein_GorostizaP.pdf | 837.55 kB | Adobe PDF | View/Open Request a copy |
Document embargat fins el
5-10-2024
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.