PROTEIN THERMAL-STABILITY - HYDROGEN-BONDS OR INTERNAL PACKING

Thermally stable proteins are of interest for several reasons. They ca n be used to improve the efficiency of many industrial processes and p rovide insight into the general mechanisms of protein folding and stab ilization. Comparison of tertiary structural properties of several pro tein families with members of different thermostability should help to delineate the role of individual factors in achieving stability at hi gh temperature. In this work, 16 protein families with at least one kn own thermophilic and one known mesophilic tertiary structure were exam ined for the number and type of hydrogen bonds and salt links, polar s urface composition, internal cavities and packing densities, and secon dary structural composition. The results show a consistent increase in the number of hydrogen bonds and in polar surface area fraction with increased thermostability.