The interaction of enoxaparin and fondaparinux with calcium

- The main sites of calcium binding were determined for enoxaparin and fondaparinux.
- HSQC pH titrations characterized the acid-base properties with and without Ca2+.
- Differences in titration curves identified structures responsible for Ca2+ binding.
- Both unsubstituted and 2-O-sulfated iduronate rings are important in Ca2+ binding.