Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance work on Wednesday 27th March 2019 from 11:00 AM to 1:00 PM (GMT).

During this time our website performance may be temporarily affected. We apologise for any inconvenience this might cause and thank you for your patience.


Issue 27, 2014
Previous Article Next Article

Reductive activation and structural rearrangement in superoxide reductase: a combined infrared spectroscopic and computational study

Author affiliations

Abstract

Superoxide reductases (SOR) are a family of non-heme iron enzymes that limit oxidative stress by catalysing the reduction of superoxide to hydrogen peroxide and, thus, represent model systems for the detoxification of reactive oxygen species. In several enzymes of this type, reductive activation of the active site involves the reversible dissociation of a glutamate from the proposed substrate binding site at the iron. In this study we have employed IR spectroscopic and theoretical methods to gain insights into redox-linked structural changes of 1Fe-type superoxide reductases, focusing on the enzyme from the archaeon Ignicoccus hospitalis. Guided by crystal structure data and complemented by spectra calculation for an active site model, the main IR difference signals could be assigned. These signals reflect redox-induced structural changes in the first coordination sphere of the iron centre, adjacent loop and helical regions, and more remote β-sheets. By comparison with the spectra obtained for the E23A mutant of Ignicoccus hospitalis SOR, it is shown that glutamate E23 dissociates reversibly from the ferrous iron during reductive activation of the wild type enzyme. Moreover, this process is found to trigger a global conformational transition of the protein that is strictly dependent on the presence of E23. Similar concerted structural changes can be inferred from the IR spectra of related SORs such as that from Archaeoglobus fulgidus, indicating a widespread mechanism. A possible functional role of this process in terms of synergistic effects during reductive activation of the homotetrameric enzyme is proposed.

Graphical abstract: Reductive activation and structural rearrangement in superoxide reductase: a combined infrared spectroscopic and computational study

Back to tab navigation

Supplementary files

Publication details

The article was received on 28 Feb 2014, accepted on 28 May 2014 and first published on 29 May 2014


Article type: Paper
DOI: 10.1039/C4CP00884G
Author version
available:
Download author version (PDF)
Citation: Phys. Chem. Chem. Phys., 2014,16, 14220-14230
  • Open access: Creative Commons BY license
  •   Request permissions

    Reductive activation and structural rearrangement in superoxide reductase: a combined infrared spectroscopic and computational study

    M. Horch, A. F. Pinto, T. Utesch, M. A. Mroginski, C. V. Romão, M. Teixeira, P. Hildebrandt and I. Zebger, Phys. Chem. Chem. Phys., 2014, 16, 14220
    DOI: 10.1039/C4CP00884G

    This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements