Summary: | 博士 === 國立交通大學 === 生物科技學系 === 103 === The Protein thermal stability is an important factor considered in medical and industrial applications. Many structural characteristics related to protein thermal stability have been elucidated, and increasing salt bridges is considered as one of the most efficient strategies to increase protein thermal stability. However, the accurate simulation of salt bridges remains difficult. In this study, based on the statistical analysis of 10,556 surface salt bridges on 6,493 X-ray protein structures, these salt bridges were first categorized depending on pairing residues, secondary structure locations, and Cα-Cα distances. Furthermore, a novel method was designed by pairing preferences to construct a salt-bridge pair index and used in a weighted electrostatic attraction model to find the effective pairings for designing salt bridges. The model was also coupled with B-factor, weighted contact number (WCN), relative solvent accessibility (RSA), and conservation prescreening to determine the positions appropriate for the thermal adaptive design of salt bridges. According to our method, the putative salt-bridges were successfully designed on a mesophilic β-glucosidase. Thus, this study demonstrated an effective method for the thermal adaptive design of salt bridges through inference of suitable positions and substitutions.
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