Sample interview questions: How do you approach studying protein-protein interactions using biophysical methods?
Sample answer:
Biophysical Techniques for Studying Protein-Protein Interactions:
1. Isothermal Titration Calorimetry (ITC)
- Measures the heat released or absorbed upon binding of protein molecules.
- Provides thermodynamic parameters (Kd, ΔH, ΔS) and stoichiometry of the interaction.
2. Surface Plasmon Resonance (SPR)
- Monitors changes in refractive index at a sensor surface upon binding of one protein immobilized on the surface to another protein in solution.
- Determines kinetic (kon, koff) and equilibrium (Kd) parameters.
3. Fluorescence Resonance Energy Transfer (FRET)
- Utilizes fluorescent dyes attached to interacting proteins.
- Measures changes in fluorescence intensity or lifetime as the proteins come into close proximity, indicating binding.
4. Nuclear Magnetic Resonance (NMR)
- Monitors structural changes in labeled proteins upon binding.
- Provides insights into the binding interface and conformational dynamics.
5. Mass Spectrometry
- Identifies and quantifies protein complexes using tec… Read full answer