title: Structural studies on heparin. Tetrasaccharides obtained by heparinase degradation.
abstract: Three tetrasaccharides representing major structural sequences of heparin were isolated in good yield and characterized after degradation of heparin by purified flavobacterial heparinase. N-Desulfation was necessary to achieve good separation of these closely related compounds from each other. One of the tetrasaccharides was shown to be derived from the fully sulfated repeating segments; to contain L-iduronic acid and six sulfate groups, and have the structure delta 4,5- HexpA -(2-SO4)-(1----4)-alpha-D- GlcpN -(N-SO4)-(6-SO4)-(1- ---4)-alpha -L- IdopA -(2-SO4)-(1----4)-D- GlcN -(N-SO4)-(6-SO4). The second contained a D-glucuronic acid unit that was nonsulfated instead of the L-iduronic acid, and the third, obtained in a fairly low yield, contained five sulfate groups, three of which being located on the disaccharide at the nonreducing end, and having the structure delta 4,5- HexpA -(2-SO4)-(1----4)-alpha-D- GlcpN -(N-SO4)-(6-SO4)-(1- ---4)-alpha -L- IdopA -(2-SO4)-(1----4)-D- GlcN -(N-SO4). All tetrasaccharides had a sulfated, unsaturated uronic acid unit at the nonreducing end, confirming that the heparinase requires sulfated L-iduronic acid units for activity.
mesh_terms: D002240:Carbohydrate Sequence; D005417:Flavobacterium / Q000201:enzymology; D006493:Heparin; D019763:Heparin Lyase; D009682:Magnetic Resonance Spectroscopy; D009844:Oligosaccharides; D011133:Polysaccharide-Lyases / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D009844:Oligosaccharides; D006493:Heparin; D011133:Polysaccharide-Lyases; D019763:Heparin Lyase