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Interaction of soluble and surface‐bound heparin binding growth‐associated molecule with heparin
Author(s) -
Fath Melissa,
VanderNoot Victoria,
Kilpeläinen Ilkka,
Kinnunen Tarja,
Rauvala Heikki,
Linhardt Robert J.
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(99)00785-1
Subject(s) - isothermal titration calorimetry , chemistry , heparin , surface plasmon resonance , dissociation constant , titration , molecule , dissociation (chemistry) , chromatography , biochemistry , organic chemistry , nanoparticle , nanotechnology , materials science , receptor
The interaction of heparin with heparin binding growth‐associated molecule (HB‐GAM) was studied using isothermal titration calorimetry (ITC) and surface plasmon resonance (SPR). ITC studies showed that, in solution, heparin bound HB‐GAM with a Δ H of −30 kcal/mole corresponding to a dissociation constant ( K d ) of 460 nM. The stoichiometry of interaction was 3 moles of HB‐GAM per mole of heparin, corresponding to a minimum heparin binding site for HB‐GAM of 12–16 saccharide residues. Kinetic measurements of heparin interaction with HB‐GAM made by SPR afforded a K d of 4 nM, suggesting considerably tighter binding when HB‐GAM was immobilized on a surface. Affinity chromatography of a sized mixture of heparin oligosaccharides, having a degree of polymerization (dp) of >14 saccharide units, on HB‐GAM‐Sepharose demonstrated that oligosaccharides having more than 18 saccharide residues showed the tightest interaction.