| Autor: |
Stenlund, Peter, Tibell, Lena A. E., Andersson, Dick |
| Zdroj: |
Protein Science: A Publication of the Protein Society; 1997, Vol. 6 Issue 11, p2350-2358, 9p |
| Abstrakt: |
Human extracellular superoxide dismutase (hEC-SOD) is a secreted tetrameric protein involved in protection against oxygen free radicals. Because EC-SOD is too large a protein for structural determination by multidimensional NMR, and attempts to crystallize the protein for X-ray structural determination have failed, the three-dimensional structure of hEC-SOD is unknown. This means that alternative strategies for structural studies are needed. The N-terminal domain of EC-SOD has already been studied using the fusion protein FusNN, comprised of the 49 N-terminal amino acids from hEC-SOD fused to human carbonic anhydrase (HCAII). The N-terminal domain in this fusion protein forms a well-defined three-dimensional structure, which probably contains α-helical elements and is responsible for the tetramerization of the protein. In this work, we have extended the studies, using site-directed mutagenesis in combination with size-exclusion chromatography, CD, and fluorescence spectroscopy, to investigate the nature of the tetrameric interaction. Our results show that the hydrophobic side of a predicted amphiphatic a-helix (formed by residues 14-32) in the N-terminal domain is essential for the subunit interaction. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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