Generation of anti-factor Xa active, 3-O-sulfated glucosamine-rich sequences by controlled desulfation of oversulfated heparins.
In the framework of a project aimed at generating heparin-like sulfation patterns and biological activities in biotechnological glycosaminoglycans, different approaches have been considered for simulating the alpha(1-->4)-linked 2-O-sulfated L-iduronic acid (IdoA2SO(3))-->N,6-O-sulfated D-glucosamine (GlcNSO(3)6SO(3)) disaccharide sequences prevalent in mammalian heparins. Since the direct approach of sulfating totally O-desulfated heparins, taken as model compounds for C-5-epimerized sulfaminoheparosan (N-deacetylated, N-sulfated Escherichia coli K5 polysaccharide), preferentially afforded heparins O-sulfated at C-3 instead than at C-2 of the iduronate residues, leading to products with low anticoagulant activities, the problem of re-generating a substantial proportion of the original IdoA2SO(3) residues was circumvented by performing controlled solvolytic desulfation (with 9:1 v/v DMSO-MeOH) of extensively sulfated heparins. The order of desulfation of major residues of heparin GlcN and IdoA and of the minor one D-glucuronic acid was: GlcNSO(3)>GlcN6SO(3)>IdoA3SO(3) congruent with GlcA2SO(3) congruent with GlcN3SO(3)>IdoA2SO(3) congruent with GlcA3SO(3). Starting from a 'supersulfated' low-molecular weight heparin, we obtained products with up to 40% of iduronate residues O-sulfated exclusively at C-2 and up to 40% of their glucosamine residues O-sulfated at both C-6 and C-3. Upon re-N-sulfation, these products displayed an in vitro antithrombotic activity (expressed as anti-factor Xa units) comparable with those of current low-molecular weight heparins.
Naggi
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A
G. Ronzoni Institute for Chemical and Biochemical Research, G. Colombo 81, Milan I-20133, Italy. naggi@ronzoni.it
De Cristofano
B
B
Bisio
A
A
Torri
G
G
Casu
B
B
D000818:Animals; D000925:Anticoagulants / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D065427:Factor Xa Inhibitors; D005944:Glucosamine / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry; D006493:Heparin / Q000737:chemistry* / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D013329:Structure-Activity Relationship; D013431:Sulfates / Q000737:chemistry / Q000494:pharmacology
D000925:Anticoagulants; D065427:Factor Xa Inhibitors; D013431:Sulfates; C065632:glucosamine 3-O-sulfate; D006493:Heparin; D005944:Glucosamine