Structural characterization of low molecular weight heparins

Low molecular weight heparins (LMWHs) obtained by different depolymerization processes can be distinguished from each other by characteristic end-residues, which are easily identified and quantified by nuclear-magnetic-resonance (NMR) spectroscopy. NMR spectroscopy characterizes major sulfation patterns as well as minor sequences such as the antithrombin-binding sequence and the linkage region of LMWHs. Artifacts associated with base-induced modifications such as the formation of iduronic acid epoxide and aziridine derivatives of N-sulfoglucosamine residues can also be detected. The influence of these modifications on the binding of heparins and LMWHs to proteins other than antithrombin are discussed.