We have located links that may give you full text access.
Charge Regulation in a Rieske Proton Pump Pinpoints Zero, One, and Two Proton-Coupled Electron Transfer.
Journal of the American Chemical Society 2023 July 25
The degree to which redox-driven proton pumps regulate net charge during electron transfer (ΔZET ) remains undetermined due to difficulties in measuring the net charge of solvated proteins. Values of ΔZET can reflect reorganization energies or redox potentials associated with ET and can be used to distinguish ET from proton(s)-coupled electron transfer (PCET). Here, we synthesized protein "charge ladders" of a Rieske [2Fe-2S] subunit from Thermus thermophilus (trunc Tt Rp) and made 120 electrostatic measurements of ΔZET across pH. Across pH 5-10, trunc Tt Rp is suspected of transitioning from ET to PCET, and then to two proton-coupled ET (2PCET). Upon reduction, we found that trunc Tt Rp became more negative at pH 6.0 by one unit (ΔZET = -1.01 ± 0.14), consistent with single ET; was isoelectric at pH 8.8 (ΔZET = -0.01 ± 0.45), consistent with PCET; and became more positive at pH 10.6 (ΔZET = +1.37 ± 0.60), consistent with 2PCET. These ΔZET values are attributed to protonation of H154 and H134. Across pH, redox potentials of Tt Rp (measured previously) correlated with protonation energies of H154 and H134 and ΔZET for trunc Tt Rp, supporting a discrete proton pumping mechanism for Rieske proteins at the Fe-coordinating histidines.
Full text links
Related Resources
Trending Papers
Review article: Recent advances in ascites and acute kidney injury management in cirrhosis.Alimentary Pharmacology & Therapeutics 2024 March 26
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app