Enghild Lab Enghild Lab Enghild Lab Enghild Lab

Extracellular superoxide dismutase (EC-SOD)

Ida B. Thøgersen, Line Rold Thomsen, Ebbe Toftgaard Poulsen, Jane Savskov Petersen, Carsten S. Sonne-Schmidt

Extracellular superoxide dismutase is the only extracellular enzyme that scavenges superoxide radicals and thus participates in sustaining the delicate red-ox balance of the extracellular space. EC-SOD is expressed in various tissues of the body, although to a larger extend in the oxygen-rich arteries and lungs.

Our research, among others, have identified EC-SOD-binding partners of the extracellular matrix including sulphated proteoglycans and collagen I. A naturally occurring truncation of EC-SOD leads to a decreased matrix-binding affinity. This processing pathway might be a regulatory mechanism, which alters the distribution of EC-SOD in the extracellular matrix.
Additionally we have discovered two variants of EC-SOD, each with different disulfide bridge patterns. One is active, with a disulfide bridge pattern similar to the intracellular Cu/Zn-SOD, while the other is inactive. Both variants arise from identical amino acid sequences, a unique occurrence. We are presently studying the structural and functional basis for this phenomenon as well as a potential role of this divergence in vivo.