Importance of 6-0-Sulfate Groups of Glucosamine Residues in Heparin for Activation of FGF-1 and FGF-2

Abstract

Treatment of the pyridinium salts of heparin with N-methyltrimethylsilyl-trifluoroacetamide (MTSTFA) in pyridine for 2 h at various temperatures caused specific 6-O-desulfations from trisulfated disaccharide units to various degrees without detectable depolymerization or other chemical changes. In order to assess the importance of 6-O-sulfate groups in N-sulfated glucosamine (GlcNS) residues to promote FGF-1 and FGF-2 activities, various 6-O-desulfated (6-O-DS-) heparins were quantitatively examined for activity as enhancers or inhibitors of specific FGF-1- and FGF-2-induced proliferation of BALB/c3T3 clone A31 (A31) cells and the chlorate-treated cells. The present results suggested that a high content of 6-O-sulfate groups in GlcNS residues was required for activation of FGF-1, but not FGF-2. However, complete 6-O-desulfation of trisulfated disaccharide units in heparin resulted in loss of the ability to activate FGF-2, although the desulfated product bound strongly to FGF-2.

Interaction of Heparan Sulfate from Mammary Cells with Acidic Fibroblast Growth Factor (FGF) and Basic FGF

“…In addition, neither the ranking, in terms of association kinetics and affinity, nor the class of binding sites for bFGF in the samples of HS correspond with the results obtained with aFGF. These results thus support the hypothesis that aFGF and bFGF may recognize different structures in HS (34,35), although the possibility remains that aFGF binds at least some of the structures recognized by bFGF, but fails to distinguish the finer features of these structures that lead to the different association kinetics observed with bFGF.…”

“…It is known that sulfated regions of heparin, which are enriched in 6-O sulfate groups on glucosamine, are important for the interaction of aFGF (34,41). However, the structural basis for the different association and dissociation rate constants of aFGF for the mammary cell HS remain to be determined.…”

Interaction of Thrombospondin-1 and Heparan Sulfate from Endothelial Cells

“…This treatment reduced the percentage of 2-O-sulfate groups-containing disaccharides from 75% in the mucosal heparin to 3%. For 6-O-desulfation the pyridinium salt of heparin (10 mg/ml pyridine) was treated with N-methyltrimethylsilyl-trifluoroacetamide (200 l/ml heparin solution) for 2 h at 100°C (42). After the addition of an equal volume of 20% methanol, the reaction mixture was dialyzed against water, adjusted to pH 9 -10 with NaOH, and dialyzed again.…”

Dynamic expression patterns of 6‐O endosulfatases during zebrafish development suggest a subfunctionalisation event for sulf2

“…Specific sulfate groups (6S) have been shown to be dispensable for FGF2-HS binding, but critical for FGF/ FGFR2 signalling (Ishihara et al, 1995), and therefore removal of the 6-O-sulfate group disrupts FGF signalling (Wang et al, 2004). Similarly, VEGF binding and activity requires moderately 6-O sulfated HS (Ashikari-Hada et al, 2005;Robinson et al, 2006) and treatment of heparin with human SULF2 abolishes its binding to VEGF (Uchimura et al, 2006).…”