MS04-P10 The Durham Screens: Fast Protein Buffer Optimisation through Differential Scanning Fluorimetry Dan Bruce (Department of Biosciences, Durham University, Durham, United Kingdom) Ehmke Pohl (Department of Biosciences, Durham University, Durham, United Kingdom)email: daniel.bruce@durham.ac.ukModern crystallographers are capable of unprecedented speed and throughput in their work, from target purification and crystallisation to diffraction data acquisition and analysis. Protein stability is a key factor in the crystallisation process; samples must be conformationally homogenous and structurally sound over a period of days to form high-quality diffracting crystals. We present The Durham Screens, a set of three complimentary 96-condition screens designed to efficiently identify conditions favourable to protein stability.

Differential Scanning Fluorimetry (DSF, also known as Thermofluor and the Thermal Shift Assay) has rapidly become the go-to method for protein stability analysis due to its high throughput, low cost and versatility. By monitoring the thermal denaturation of a protein sample using either its intrinsic fluorescence or an environmentally-sensitive fluorescent dye, DSF can compare a range of conditions and identify those that confer the greatest thermal stability.

The Durham Screens are designed around three themes: pH, salts and osmolytes. By deconvoluting the contributions of each buffer component to the overall stability of a protein sample, the screens provide valuable insights to optimise purification protocols, protect stored samples and guide rationally-designed crystallisation trials.
 
References:

Grøftehauge, M. K., Hajizadeh, N. R., Swann, M. J., & Pohl, E. (2015). Protein–ligand interactions investigated by thermal shift assays (TSA) and dual polarization interferometry (DPI). (2015) Acta Crystallographica Section D: Biological Crystallography, 71(1), 36-44.
Keywords: Sample optimisation, DSF