Heparin dodecasaccharide containing two antithrombin-binding pentasaccharides: structural features and biological...

Area of Science:

• Biochemistry
• Pharmacology
• Glycobiology

Background:

• Antithrombin (AT) binding of heparin derivatives is crucial for anticoagulant activity.
• The pentasaccharide sequence AGA*IA is a key determinant of AT binding.
• Existing low molecular weight heparins (LMWHs) have limitations in efficacy and specificity.

Purpose of the Study:

• To isolate and characterize novel heparin-derived oligosaccharides with improved antithrombotic properties.
• To investigate the structure-activity relationship of a newly identified dodecasaccharide.
• To evaluate the antithrombotic potential of the novel compound compared to existing therapies.

Main Methods:

• Highly chemoselective depolymerization of heparin to create ultra-low molecular weight heparin.
• Advanced separation techniques for polysaccharide isolation.
• Characterization using NMR spectroscopy, fluorescence titration, and LC-MS.
• Assessment of antithrombin binding affinity and anti-Factor Xa (FXa) activity.

Main Results:

• Isolation of a dodecasaccharide with a unique, biosynthetically unexpected structure.
• The dodecasaccharide contains two contiguous AT-binding sequences separated by a nonsulfated iduronate.
• Demonstrated significantly increased anti-FXa activity compared to pentasaccharide, fondaparinux, and enoxaparin.

Conclusions:

• The novel dodecasaccharide possesses potent antithrombotic properties due to its unique structure and enhanced AT binding.
• This finding opens new avenues for developing more effective heparin-based anticoagulants.
• The study highlights the potential of advanced depolymerization and separation techniques in discovering novel bioactive oligosaccharides.