Activation of Proton Translocation by Respiratory Complex I.

Belevich, Nikolai; von Ballmoos, Christoph; Verkhovskaya, Marina (2017). Activation of Proton Translocation by Respiratory Complex I. Biochemistry, 56(42), pp. 5691-5697. American Chemical Society 10.1021/acs.biochem.7b00727

[img]
Preview
Text
document.pdf - Accepted Version
Available under License Publisher holds Copyright.

Download (1MB) | Preview

Activation of proton pumping by reconstituted and native membrane-bound Complex I was studied using optical electric potential- and pH-sensitive probes. We find that reconstituted Complex I has a delay in proton translocation, which is significantly longer than the delay in quinone reductase activity, indicating an initially decoupled state of Complex I. Studies of the amount of NADH required for the activation of pumping indicate the prerequisite of multiple turnovers. Proton pumping by Complex I was also activated by NADPH, excluding significant reduction of Complex I and a preexisting Δψ as activation factors. Co-reconstitution of Complex I and ATPase did not indicate an increased membrane permeability for protons in the uncoupled Complex I state. The delay in Complex I proton pumping activation was also observed in subbacterial vesicles. While it is negligible at room temperature, it strongly increases at a lower temperature. We conclude that Complex I undergoes a conversion from a decoupled state to a coupled state upon activation. The possible origins and importance of the observed phenomenon are discussed.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Departement of Chemistry and Biochemistry

UniBE Contributor:

von Ballmoos, Christoph

Subjects:

500 Science > 570 Life sciences; biology
500 Science > 540 Chemistry

ISSN:

1520-4995

Publisher:

American Chemical Society

Language:

English

Submitter:

Christoph von Ballmoos

Date Deposited:

13 Apr 2018 15:30

Last Modified:

01 Nov 2018 02:31

Publisher DOI:

10.1021/acs.biochem.7b00727

PubMed ID:

28960069

BORIS DOI:

10.7892/boris.112615

URI:

https://boris.unibe.ch/id/eprint/112615

Actions (login required)

Edit item Edit item
Provide Feedback