Fucoidan-Dependent Conformational Changes in Annexin II Tetramer
| Autor: | David M. Waisman, Peter Louie, Carol E. Braat, Akhil Manro, Geetha Kassam, Sandra L. Fitzpatrick |
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| Rok vydání: | 2000 |
| Předmět: |
Conformational change
Protein Conformation Molecular Sequence Data Phospholipid Peptide Sulfuric Acid Esters Biochemistry chemistry.chemical_compound Sulfation Tetramer Polysaccharides Amino Acid Sequence Annexin A2 Fucose chemistry.chemical_classification Binding Sites Dose-Response Relationship Drug Heparin Fucoidan Circular Dichroism Biological activity Seaweed chemistry Liposomes Calcium Protein Binding |
| Zdroj: | Biochemistry. 39:2140-2148 |
| ISSN: | 1520-4995 0006-2960 |
| DOI: | 10.1021/bi992180z |
| Popis: | Fucoidan, a sulfated fucopolysaccharide, mimics the fucosylated glycans of glycoproteins and has therefore been used as a probe for investigating the role of membrane polysaccharides in cell-cell adhesion. In the present report we have characterized the interaction of fucoidan with the Ca(2+)- and phospholipid-binding protein annexin II tetramer (AIIt). AIIt bound to fucoidan with an apparent K(d) of 1.24 +/- 0.69 nM (mean +/- SD, n = 3) with a stoichiometry of 0.010 +/- 0.001 mol of fucoidan/mol of AIIt (mean +/- SD, n = 3). The binding of fucoidan to AIIt was Ca(2+)-independent. Furthermore, in the presence but not the absence of Ca(2+), the binding of fucoidan to AIIt caused a decrease in the alpha-helical content from 32% to 7%. A peptide corresponding to a region of the p36 subunit of AIIt, F(306)-S(313), which contains a Cardin-Weintraub consensus sequence for heparin binding, was shown to undergo a conformational change upon fucoidan binding. This suggests that heparin and fucoidan bound to this region of AIIt. The binding of fucoidan but not heparin by AIIt also inhibited the ability of AIIt to bind to and aggregate phospholipid liposomes. These results suggest that the binding of AIIt to the carbohydrate conjugates of certain membrane glycoproteins may have profound effects on the structure and biological activity of AIIt. |
| Databáze: | OpenAIRE |
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