Thermostability

Thermostability is the capacity of a substance to retain its structure, activity, and integrity at elevated temperatures or to resist thermal degradation. It is a central concern in biochemistry, pharmacology, materials science, and industrial applications, where heat exposure can affect performance, shelf life, and safety.

In biology, thermostability is often discussed for proteins and nucleic acids. For proteins, it denotes resistance to unfolding, aggregation, or loss of activity as temperature rises. Metrics commonly used include melting temperature (Tm) and residual activity after heating, sometimes expressed as half-life at a given temperature.

Thermostability is measured by techniques such as differential scanning calorimetry (DSC), differential scanning fluorimetry (DSF), circular dichroism (CD) spectroscopy, and thermogravimetric analysis (TGA). Additional practical indicators include decomposition temperature and the temperature at which activity falls by 50 percent.

Determinants of thermostability involve intrinsic features like strong hydrophobic cores, disulfide bonds, salt bridges, and compact folds, as well as extrinsic factors such as pH, solvent conditions, ligands, and formulation. Strategies to enhance thermostability include protein engineering (directed evolution, consensus design, disulfide engineering), glycosylation, and stabilizing additives or immobilization.

Applications include industrial enzymes that operate at high temperatures, enabling faster reactions and reduced contamination; vaccines and biologics that require stable formulations for distribution without cold chains; and polymers or catalysts where thermal resistance is essential. Improvements in thermostability often involve trade-offs with activity or flexibility.