thermostabile

Thermostabile is an adjective used in Italian and scientific contexts to describe a substance that remains stable at elevated temperatures. In biology and biotechnology, it is commonly applied to proteins, enzymes, nucleic acids, and microorganisms that retain structure and activity when heated. The English equivalent is thermostable.

Thermostability is commonly quantified by melting temperature (Tm), the temperature at which half of the molecules are unfolded, and by residual activity or half-life at a given high temperature. A higher Tm or longer t1/2 indicates greater thermostability. Factors that influence stability include a densely packed hydrophobic core, extensive salt bridges, stabilizing disulfide bonds, reduced conformational flexibility, and, in some cases, post-translational modifications such as glycosylation.

In practical terms, thermostable enzymes enable industrial processes at high temperatures, offering advantages such as faster kinetics and lower risk of microbial contamination. A well-known example is Taq polymerase, a DNA polymerase derived from Thermus aquaticus, which functions during high-temperature PCR. Other thermostable enzymes are sourced from thermophilic organisms such as Geobacillus, Thermotoga, and Pyrococcus species.

Developing thermostability commonly employs directed evolution, rational design, or a combination of both to increase Tm and maintain catalytic efficiency. Analytical methods such as differential scanning calorimetry (DSC), circular dichroism (CD), and differential scanning fluorimetry (DSF) are used to assess thermal unfolding, while activity assays measure functional stability.