Factors influencing the stability of alpha-helices and beta-strands in thermophilic Ribonuclease H

Understanding the influence of structural parameters is crucial to enhance the thermal stability of proteins. In this work, the stability (DeltaG) of residues in different secondary structures of Ribonuclease H (RNase H) has been analyzed with 48 amino acid properties. The properties reflecting hydr ophobicity show a good correlation with stability. Further, the linear distribution of surrounding hydrophobicity in alpha -he lices, obtained from the three dimensional structure of thermophilic RNase H, agrees well with experimental DeltaG values. Moreover, the stability par ameters correlate better in alpha -helices than those did in beta -strand s egments. Multiple regression analysis, incorporating combinations of three propertie s from among all possible combinations of the 48 properties, increased the correlation coefficient to 0.77.