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Relation between binding free energy and solubility

  1. Jan 16, 2012 #1
    Suppose we have a ligand binding to a receptor in solvent medium. I am interested to know whether there is any relation between "Binding free energy" and "Solubility".

    Extemely sorry if I posted my question in the wrong section. I'd be glad if anyone could help me out with this.

    Chirag V. Vora
    Department of Pharmacoinformatics,
    Block - A, Bioinformatics Infrastructure Facility,
    National Institute of Pharmaceutical Education and Research (NIPER)
    Sector 67, S.A.S. Nagar,
    Punjab (INDIA) - 160 062
  2. jcsd
  3. Jan 16, 2012 #2


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    That's not only a question of energetics but even more of entropy.
    The equilibrium constant for dissociation can be calculated from
    [itex]\Delta G=\Delta H -T \Delta S \approx \Delta U -T \Delta S [/itex]
    where [itex] \Delta U [/itex] is the dissociation energy per mole and in solution is practically equal to the enthalpy change,
    and [itex] \Delta S [/itex] the entropic change due to dissociation.
    The equilibrium constant K is
    [itex] K=\exp(\Delta G/RT) [/itex]

    Edit: Excuse me, I overread "free" in your post.
    [itex] \Delta G[/itex] is the free energy of binding, so the relation is quite direct.
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