Protein Interactions Analysis

The Protein Interactions Analysis capability enables the study of protein-protein and protein-ligand interactions using various techniques including, analytical ultracentrifugation, to determine the native mass, stoichiometry and shape of proteins and biomolecular complexes in solution, isothermal titration microcalorimetry (ITC) and microscale thermophoresis (MST) to measure the thermodynamics of the interactions, and surface plasmon resonance (SPR) spectroscopy to measure binding kinetics.


This capability is home to a range of instrumentation listed here

Biacore T200 Surface Plasmon Resonance - for proteins and biomolecular complexes, it provides kinetic, affinity, concentration, specificity and thermodynamic interaction data in real time with exceptional sensitivity.

Beckman Coulter Model XL-A Analytical Ultracentrifuge equipped with an Aviv Fluorescence
Detection System
- uses centrifugal force coupled to sensitive absorbance or fluorescence detection to determine the native molecular mass, shape and binding thermodynamics (i.e. affinity & stoichiometry) of proteins and biomolecular complexes in solution.

MicroCal iTC200 Isothermal Titration Microcalorimeter - measures the change in heat accompanying the titration of a ligand (e.g. drug) with an acceptor (e.g. protein) to permit the determination of affinity, stoichiometry and other molecular properties.

NanoTemper Monolith NT.115 RG Microscale Thermophoresis Instrument - uses the process of thermophoresis (i.e. a temperature gradient) to measure binding of an interacting partner (e.g. peptide, protein or ligand) to a fluorescently labelled acceptor protein.

NanoTemper Monolith Label Free Microscale Thermophoresis Instrument - employs thermophoresis to measure binding of an interacting partner to an acceptor protein using intrinsic aromatic amino acid fluorescence.

AVIV model 420 Circular Dichroism Spectrometer - A UV-Vis spectrophotometer for measuring circular dichroism (CD) as a function of wavelength, time, temperature, pH, and concentration. This system complements NMR and X-ray diffraction for characterizing biological and synthetic molecules.


There are a broad range of research questions that can be addressed within this capability:

  • Circular Dichroism:
    • 2° structure: α, β, turn & random
    • Determine if protein/peptide is folded
    • Thermal denaturation
  • Isothermal Titration Microcalorimetry:
    • Thermodynamic parameters: ΔG, KD, ΔH, ΔS & N
  • Analytical Ultracentrifugation:
    • sedimentation coefficient (s)
    • diffusion coefficient (D)
    • mass (M)/oligomeric state
    • shape (f/f0)
    • rate constants (kon/koff)
    • native mass (M) (accurate)
    • oligomeric state
    • affinity of interactions (KD)
    • stoichiometry (N)
    • sample stability
  • Microscale Thermophoresis:
    • Affinity (KD)
    • Stoichiometry (N)
    • Enzyme Kinetics (KM, Kcat)
    • ΔG, ΔH & ΔS (van’t Hoff method)
  • surface plasmon resonance:
    • Rate constants (kon, koff)
    • Affinity (KD)


Contact us to discuss your research applications:

  • Research Contracts for bespoke projects
  • Academic collaboration

Contact Us

For more information and to discuss your requirements please contact:

Professor Marc Kvansakul