Exact theory of sedimentation equilibrium made useful

  • Peter R. Wills
  • Donald J. Winzor
Conference paper
Part of the Progress in Colloid and Polymer Science book series (PROGCOLLOID, volume 119)


The exact description of the thermodynamics of solutions has been used to describe, without approximation, the distribution of all the components of an incompressible solution in a centrifuge cell at sedimentation equilibrium. Thermodynamic parameters describing the interactions between solute components of known molar mass can be obtained by direct analysis of the experimental data.

Interpretation of the measured thermodynamic parameters in terms of molecular interactions requires that an arbitrary distinction be made between nonassociative forces, like hard-sphere volume-exclusion and mean-field electrostatic repulsion or attraction, and specific short-range forces of association that give rise to the formation of molecular aggregates. Provided the former can be accounted for adequately, the effects of the latter can be elucidated in the form of good estimates of the equilibrium constants for the reactions of aggregation.

Key words

Sedimentation equilibrium Molecular interactions Thermodynamic nonideality Equilibrium constants 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    McMillan WG, Mayer JE (1945) J Chem Phys 13:276CrossRefGoogle Scholar
  2. 2.
    Hill TL (1955) J Chem Phys 23:623CrossRefGoogle Scholar
  3. 3.
    Hill TL (1955) J Chem Phys 23:2270CrossRefGoogle Scholar
  4. 4.
    Casassa EF, Eisenberg H (1964) Adv Protein Chem 19:287CrossRefGoogle Scholar
  5. 5.
    Prigogine I, Defay R (1954) Chemical thermodynamics (Everett DH translator). Longhams, LondonGoogle Scholar
  6. 6.
    Mayer JE (1950) J Chem Phys 18:1426CrossRefGoogle Scholar
  7. 7.
    Winzor DJ, Wills PR (1994) In: Schuster TM, Laue TM (eds) Modern analytical ultracentrifugation. Birkhä-user, Boston, pp 66–80Google Scholar
  8. 8.
    Wills PR, Jacobsen MP, Winzor DJ (1996) Biopolymers 38:119CrossRefGoogle Scholar
  9. 9.
    Williams JW, Van Holde KE, Baldwin RL, Fujita H (1958) Chem Revs 58:715CrossRefGoogle Scholar
  10. 10.
    Hill TL, Chen YD (1973) Biopolymers 12:1285CrossRefGoogle Scholar
  11. 11.
    Wills PR, Hall DR, Winzor DJ (2000) Biophys Chem 84:217CrossRefGoogle Scholar
  12. 12.
    Hill TL (1956) Discuss Faraday Soc 21:31CrossRefGoogle Scholar
  13. 13.
    Wills PR, Winzor DJ (1993) Biopolymers 33:1627CrossRefGoogle Scholar
  14. 14.
    Fujita, H (1994) In: Schuster TM, Laue TM (eds) Modern analytical ultracentrifugation. Birkhäuser, Boston, pp 3–14Google Scholar
  15. 15.
    Jansons KM, Phillips CG (1990) J Colloid Interface Sci 137:75CrossRefGoogle Scholar
  16. 16.
    Wills PR, Georgalis Y, Dijk J, Winzor DJ (1995) Biophys Chem57:37CrossRefGoogle Scholar
  17. 17.
    Wills PR, Jacobsen MP, Winzor DJ (2000) Biophys J 79:2178CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2002

Authors and Affiliations

  • Peter R. Wills
    • 1
    • 2
  • Donald J. Winzor
    • 3
  1. 1.Department of PhysicsUniversity of AucklandAucklandNew Zealand
  2. 2.GMD - German National Research Center for Information TechnologySchloss BirlinghovenGermany
  3. 3.Centre for Protein Structure Function and Engineering Department of BochemistryUniversity of QueenslandBrisbaneAustralia

Personalised recommendations