title: Extracellular superoxide dismutase (EC-SOD) binds to type i collagen and protects against oxidative fragmentation.
abstract: The antioxidant enzyme extracellular superoxide dismutase (EC-SOD) is mainly found in the extracellular matrix of tissues. EC-SOD participates in the detoxification of reactive oxygen species by catalyzing the dismutation of superoxide radicals. The tissue distribution of the enzyme is particularly important because of the reactive nature of its substrate, and it is likely essential that EC-SOD is positioned at the site of superoxide production to prevent adventitious oxidation. EC-SOD contains a C-terminal heparin-binding region thought to be important for modulating its distribution in the extracellular matrix. This paper demonstrates that, in addition to binding heparin, EC-SOD specifically binds to type I collagen with a dissociation constant (K(d)) of 200 nm. The heparin-binding region was found to mediate the interaction with collagen. Notably, the bound EC-SOD significantly protects type I collagen from oxidative fragmentation. This expands the known repertoire of EC-SOD binding partners and may play an important physiological role in preventing oxidative fragmentation of collagen during oxidative stress.
authors.affiliation: Departments of Molecular Biology and Medical Biochemistry, University of Aarhus, DK-8000 Aarhus C, Denmark.
authors.forename: Steen V
authors.initials: SV
authors.lastname: Petersen
authors.forename: Tim D
authors.initials: TD
authors.lastname: Oury
authors.forename: Louise
authors.initials: L
authors.lastname: Ostergaard
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Valnickova
authors.forename: Joanna
authors.initials: J
authors.lastname: Wegrzyn
authors.forename: Ida B
authors.initials: IB
authors.lastname: Thøgersen
authors.forename: Christian
authors.initials: C
authors.lastname: Jacobsen
authors.forename: Russell P
authors.initials: RP
authors.lastname: Bowler
authors.forename: Cheryl L
authors.initials: CL
authors.lastname: Fattman
authors.forename: James D
authors.initials: JD
authors.lastname: Crapo
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Enghild
mesh_terms: D000818:Animals; D000906:Antibodies; D002417:Cattle; D002846:Chromatography, Affinity; D024042:Collagen Type I / Q000276:immunology / Q000378:metabolism*; D005110:Extracellular Space / Q000201:enzymology; D006493:Heparin / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology*; D017434:Protein Structure, Tertiary; D011817:Rabbits; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000906:Antibodies; D024042:Collagen Type I; D017382:Reactive Oxygen Species; D006493:Heparin; D013482:Superoxide Dismutase