Quantitative Methods for Macromolecular Interactions

The Quantitative Methods for Macromolecular Interactions (QMMI) Unit of the BEPS Shared Resource is located on the 3rd floor of Building 13 on the NIH campus in Bethesda, MD. Please contact us to schedule a meeting or tour our labs.

We have expertise in:

  • Characterization of individual macromolecules
  • Characterization of interactions of macromolecules (self- and hetero association) and small ligands

QMMI is experienced in the application of a wide array of state-of-the-art biophysical instrumentation toward the characterization of individual macromolecules, as well as their interactions with other macromolecules or small ligands. This characterization may include:

  • Determination of equilibrium binding constants
    • thermodynamics (Delta G, Delta H, Delta Cp)
    • kinetics (kon, koff)

  • Measurement of solution-phase molecular weight, sedimentation coefficients, and translational diffusion coefficients, hydrodynamic radius, and overall asymmetry of macromolecules or their assemblies
  • Establishment of the stoichiometry of complexes
  • Insight into secondary structure or changes in structure upon ligand binding

The following analytical techniques are available within the QMMI Unit. Click here for pricing information.

Analytical ultracentrifugation (AUC) SV/SE

  • Brown PH, Balbo A, Schuck P. On the analysis of sedimentation velocity in the study of protein complexes. Eur Biohpys J, 38, (8), 1079-1099, 2009.
  • Balbo A, Zhao H, Brown PH, Schuck P. Assembly, loading, and alignment of an analytical ultracentrifuge sample cell. J Vis Exp, 33, pii 1530, 2009.
  • Brown PH, Balbo A, and Schuck P. Characterizing protein-protein interactions by sedimentation velocity analytical ultracentrifugation. Current Protocols in Immunology, Chapter 18: Unit 18.15, 2008.
  • Balbo A, Brown PH, Braswell EH, and Schuck P. Measuring protein-protein interactions by equilibrium sedimentation. Current Protocols in Immunology, Chapter 18: Unit 18.8, 2007.
  • Lebowitz J, Lewis MS, Schuck P. Protein Science, 11:2067-2079, 2002.

Isothermal titration calorimetry (ITC)

  • Jelesarov I and Bosshard HR. Journal of Molecular Recognition, 12:3-18, 1999.
  • Pierce MM, Raman CS, Nall BT. Methods, 19:213-221, 1999.
  • Velazquez-Campoy A, Leavitt, SA, Freire E. Methods in Molecular Biology, 261:35 -54, 2004.

Dynamic light scattering (DLS)

  • Wyatt, PJ. Analytica Chimica Acta, 272:1-40, 1993. Surface Plasmon Resonance (SPR)

Surface Plasmon Resonance (SPR)

Differential scanning calorimetry (DSC)

  • Cooper AM, Nutley, A and Wadwood A. Differential scanning microcalorimetry. In Protein-ligand Interactions: hydrodynamics and calorimetry, pp. 287-318. Edited by S. E. Harding & B. Z. Chowdry, New York: Oxford University Press, 2000.
  • Jelesarov I and Bosshard HR. Journal of Molecular Recognition, 12, 3-18, 1999.

Circular dichroism spectroscopy (CDS

  • Kelly S and Price N. Current Protocols in Protein Science, 20.10.1 – 20.10.18, 2006.
  • Kelly S, Ness, TJ, and Price, N. Biochimica et Biophysica Acta, 1751:119-139, 2005.
  • Provencher SW and Glöckner J Biochemistry, 20:33-37, 1981

Asymmetric flow field-flow fractionation (AF4)

  • Ratanathanawongs SK and Williams DL. J Sep Sci, 29:1720 – 1732, 2006.
  • Fraunhofer W and Winter G. European Journal of Pharmaceutics and Biopharmaceutics, 58: 369-383, 2004.
  • Fraunhofer W, Winter G, and Coester C. Anal Chem, 76:1909-1920, 2004.


  • Lee, C. Y. 2009. Fluorescence Spectroscopy. Current Protocols Essential Laboratory Techniques. 2:2.4.1–2.4.29. DOI: 10.1002/9780470089941.et0204s02
Zhao HBerger AJBrown PHKumar JBalbo AMay CACasillas ELaue TMPatterson GHMayer MLSchuck P
J. Gen. Physiol.
2012 May

Zhao HBrown PHBalbo AFernández-Alonso Mdel CPolishchuck NChaudhry CMayer MLGhirlando RSchuck P
Macromol Biosci
2010 Jul 07

Zhi LMans JPaskow MJBrown PHSchuck PJonjić SNatarajan KMargulies DH
2010 Mar 23

Jian XBrown PSchuck PGruschus JMBalbo AHinshaw JERandazzo PA
J. Biol. Chem.
2009 Jan 16