Study of the thermostability of protein samples

Determination of the denaturation temperature of a protein sample

The Thermal Shift Assay (TSA) technique measures the denaturation temperature variation in a protein sample during a rapid temperature gradient in function of experimental conditions. The fluorescent dye Sypro Orange is used to measure the exposure of the protein hydrophobic regions during its denaturation. The main applications of this technique are:

• Improvement of protein stability conditions (protein purification and conservation) by screening of different buffer conditions (pH, salts, additives).
• Measurement of mutation and deletion effects on protein stability.
• Screening of potential interactions between a protein and different ligands (peptides, chemical library).

Similarly, NanoDSF allows to determine the denaturation temperature of a protein sample. It is based on the fluorescence variation ratio of tryptophan and tyrosine contained in the protein in function of the temperature. The main applications of this technique are:

• Quality control of protein samples.
• Study of protein and peptide thermal stability in the presence or absence of ligands, detergents, additives, etc.
• Screening of conditions of protein preparation and storage.

Example of denaturation curve obtained on a protein of interest with Nanotemper™ Tycho NT.6

Thermal Shift Assay

Nano DSF