Scavenging of superoxide by a membrane-bound superoxide oxidase.

Lundgren, Camilla A K; Sjöstrand, Dan; Biner, Olivier; Bennett, Matthew; Rudling, Axel; Johansson, Ann-Louise; Brzezinski, Peter; Carlsson, Jens; von Ballmoos, Christoph; Högbom, Martin (2018). Scavenging of superoxide by a membrane-bound superoxide oxidase. Nature chemical biology, 14(8), pp. 788-793. Springer Nature 10.1038/s41589-018-0072-x

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Superoxide is a reactive oxygen species produced during aerobic metabolism in mitochondria and prokaryotes. It causes damage to lipids, proteins and DNA and is implicated in cancer, cardiovascular disease, neurodegenerative disorders and aging. As protection, cells express soluble superoxide dismutases, disproportionating superoxide to oxygen and hydrogen peroxide. Here, we describe a membrane-bound enzyme that directly oxidizes superoxide and funnels the sequestered electrons to ubiquinone in a diffusion-limited reaction. Experiments in proteoliposomes and inverted membranes show that the protein is capable of efficiently quenching superoxide generated at the membrane in vitro. The 2.0 Å crystal structure shows an integral membrane di-heme cytochrome b poised for electron transfer from the P-side and proton uptake from the N-side. This suggests that the reaction is electrogenic and contributes to the membrane potential while also conserving energy by reducing the quinone pool. Based on this enzymatic activity, we propose that the enzyme family be denoted superoxide oxidase (SOO).

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Department of Chemistry, Biochemistry and Pharmaceutical Sciences (DCBP)

UniBE Contributor:

Biner, Olivier Felix and von Ballmoos, Christoph

Subjects:

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

ISSN:

1552-4469

Publisher:

Springer Nature

Language:

English

Submitter:

Christoph von Ballmoos

Date Deposited:

03 Nov 2020 08:34

Last Modified:

03 Nov 2020 08:42

Publisher DOI:

10.1038/s41589-018-0072-x

PubMed ID:

29915379

BORIS DOI:

10.7892/boris.147128

URI:

https://boris.unibe.ch/id/eprint/147128

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