| Glycosaminoglycans are widely distributed in animal tissues and have important biological functions. Heparin, polysulfated glycosaminoglycan, is known to prevent blood clotting. Parent heparin is heterogeneous and difficult to purify. Its enzymatically digested and purified short fragments can be studied by various methods, providing structural models for parent heparin. Studies of heparin fragments help to answer questions regarding native heparin.;Solution conformations of heparin tetra- and hexasaccharides are investigated by ;;;Heparin pentasaccharide interactions with different ATIII models are studied by computational methods. Specific pentasaccharide binds preferably in a unique orientation. Regular pentasaccharide binds less favorably. Analysis of intermolecular interactions between pentasaccharide and intact or cleaved ATIII is used to explain the lower heparin affinity for the cleaved protein form. |
