liu.seSearch for publications in DiVA
Change search
ReferencesLink to record
Permanent link

Direct link
Characterization of the Heparin Binding of Human Extracellular Superoxide Dismutase
Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Division of cell biology.ORCID iD: 0000-0002-4694-5611
Medical chemistry Umeå.
Biochemistry Umeå.
2000 (English)In: Biochemistry, ISSN 0006-2960, Vol. 39, 230-236 p.Article in journal (Refereed) Published
Abstract [en]

 The C-terminal domain of human extracellular superoxide dismutase (hEC-SOD) plays a crucial role in the protein's interaction with heparin. Here we investigated this interaction in more detail by comparing the heparin-binding characteristics of two variants of hEC-SOD: the two fusion proteins containing the hEC-SOD C-terminal domain and a synthetic peptide homologous to the C-terminal. The interaction studies were performed using a surface plasmon resonance based technique on a BIAcore system. It should be emphasized that this is a model system. However, the kinetic constants, as measured, are valid in a comparative sense. Comparison of affinities for size-fractionated heparins revealed that octa- or decasaccharides are the smallest heparin fragments that can efficiently interact with the C-terminal domain of hEC-SOD. At physiological salt concentration, and pH 7.4, the hEC-SOD/heparin interaction was found to be of a high-affinity type, with an equilibrium dissociation constant, Kd, of 0.12 M, which is 700 and 10-20 times lower than the Kd values for the synthetic peptide and the fusion proteins, respectively. However, when an -helical structure was induced in the synthetic peptide, by addition of 10% trifluoroethanol, the Kd decreased to 0.64 M. The differences in the Kd values were mainly governed by differences in the association rate constants (kass). The hEC-SOD/heparin interaction itself was found to have a fairly high dissociation rate constant (0.1 s-1), and a very high association rate constant (8 × 105 M-1 s-1), suggesting that the interaction is mainly controlled by the association. These results together with circular dichroism spectra of the synthetic peptide suggest that an -helical structure in the C-terminal is essential for optimal binding to heparin and that other parts of hEC-SOD moderate the affinity. Our data also demonstrate that the tetramerization itself does not substantially increase the affinity.

Place, publisher, year, edition, pages
2000. Vol. 39, 230-236 p.
National Category
Medical and Health Sciences
URN: urn:nbn:se:liu:diva-39492Local ID: 49032OAI: diva2:260341
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2016-05-04

Open Access in DiVA

No full text

Other links

Search in DiVA

By author/editor
Tibell, Lena
By organisation
Faculty of Health SciencesDivision of cell biology
In the same journal
Medical and Health Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 122 hits
ReferencesLink to record
Permanent link

Direct link