Fucoidan-dependent conformational changes in annexin II tetramer

Citation
Sl. Fitzpatrick et al., Fucoidan-dependent conformational changes in annexin II tetramer, BIOCHEM, 39(9), 2000, pp. 2140-2148
Citations number
54
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
BIOCHEMISTRY
ISSN journal
0006-2960 → ACNP
Volume
39
Issue
9
Year of publication
2000
Pages
2140 - 2148
Database
ISI
SICI code
0006-2960(20000307)39:9<2140:FCCIAI>2.0.ZU;2-8
Abstract
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 repo rt we have characterized the interaction of fucoidan with the Ca2+- and pho spholipid-binding protein annexin II tetramer (AIIt). AIIt bound to fucoida n with an apparent K-d of 1.24 +/- 0.69 nM (mean +/- SD, n = 3) with a stoi chiometry of 0.010 +/- 0.001 mel of fucoidan/mol of AIIt (mean +/- SD, n 3) . The binding of fucoidan to AIIt was Ca2+-independent. Furthermore, in the presence but not the absence of Ca2+, the binding of fucoidan to AIIt caus ed a decrease in the alpha-helical content from 32% to 7%. A peptide corres ponding to a region of the p36 subunit of AIIt, F(306)-S(313), which contai ns a Cardin-Weintraub consensus sequence for heparin binding, was shown to undergo a conformational change upon fucoidan binding. This suggests that h eparin and fucoidan bound to this region of AIIt. The binding of fucoidan b ut not heparin by Ant also inhibited the ability of AIIt to bind to and agg regate phospholipid liposomes. These results suggest that the binding of AI It to the carbohydrate conjugates of certain membrane glycoproteins may hav e profound effects on the structure and biological activity of AIIt.