New insights on the specificity of heparin and heparan sulfate lyases from Flavobacterium heparinum revealed by the use of synthetic derivatives of K5 polysaccharide from E. coli and 2-O-desulfated heparin

• Published in: Glycoconjugate journal 1999-06, Vol.16 (6), p.265-270
• Main Authors: Nader, H B, Kobayashi, E Y, Chavante, S F, Tersariol, I L, Castro, R A, Shinjo, S K, Naggi, A, Torri, G, Casu, B, Dietrich, C P
• Format: Article
• Language: English
• Subjects: Acids; Bacterial Capsules; Carbohydrate Sequence; Chromatography, High Pressure Liquid; E coli; Escherichia coli - chemistry; Flavobacterium - chemistry; Heparan sulfate; Heparin - chemistry; Heparin Lyase - chemistry; Heparitin Sulfate - chemistry; Molecular Sequence Data; Polysaccharide-Lyases - chemistry; Polysaccharides, Bacterial - chemistry; Substrate Specificity
• ISSN: 0282-0080; 1573-4986
• DOI: 10.1023/A:1007057826179

The capsular polysaccharide from E. Coli, strain K5 composed of ...-->4)beta-D-GlcA(1-->4)alpha-D-GlcNAc(1-->4)beta-D-GlcA (1-->..., chemically modified K5 polysaccharides, bearing sulfates at C-2 and C-6 of the hexosamine moiety and at the C-2 of the glucuronic acid residues as well as 2-O desulfated heparin were used as substrates to study the specificity of heparitinases I and II and heparinase from Flavobacterium heparinum. The natural K5 polysaccharide was susceptible only to heparitinase I forming deltaU-GlcNAc. N-deacetylated, N-sulfated K5 became susceptible to both heparitinases I and II producing deltaU-GlcNS. The K5 polysaccharides containing sulfate at the C-2 and C-6 positions of the hexosamine moiety and C-2 position of the glucuronic acid residues were susceptible only to heparitinase II producing deltaU-GlcNS,6S and deltaU,2S-GlcNS,6S respectively. These combined results led to the conclusion that the sulfate at C-6 position of the glucosamine is impeditive for the action of heparitinase I and that heparitinase II requires at least a C-2 or a C-6 sulfate in the glucosamine residues of the substrate for its activity. Iduronic acid-2-O-desulfated heparin was susceptible only to heparitinase II producing deltaU-GlcNS,6S. All the modified K5 polysaccharides as well as the desulfated heparin were not substrates for heparinase. This led to the conclusion that heparitinase II acts upon linkages containing non-sulfated iduronic acid residues and that heparinase requires C-2 sulfated iduronic acid residues for its activity.