Extracellular superoxide dismutase exists as an octamer.


Journal Article

Human extracellular superoxide dismutase (EC-SOD) is involved in the defence against oxidative stress induced by the superoxide radical. The protein is a homotetramer stabilised by hydrophobic interactions within the N-terminal region. During the purification of EC-SOD from human aorta, we noticed that material with high affinity for heparin-Sepharose formed not only a tetramer but also an octamer. Analysis of the thermodynamic stability of the octamer suggested that the C-terminal region is involved in formation of the quaternary structure. In addition, we show that the octamer is composed of both aEC-SOD and iEC-SOD folding variants. The presence of the EC-SOD octamer with high affinity may represent a way to influence the local concentration of EC-SOD to protect tissues specifically sensitive to oxidative damage.

Full Text

Cited Authors

  • Due, AV; Petersen, SV; Valnickova, Z; Østergaard, L; Oury, TD; Crapo, JD; Enghild, JJ

Published Date

  • February 2, 2006

Published In

Volume / Issue

  • 580 / 5

Start / End Page

  • 1485 - 1489

PubMed ID

  • 16469315

Pubmed Central ID

  • 16469315

Electronic International Standard Serial Number (EISSN)

  • 1873-3468

International Standard Serial Number (ISSN)

  • 0014-5793

Digital Object Identifier (DOI)

  • 10.1016/j.febslet.2006.01.081


  • eng