All-atom contact potential approach to protein thermostability analysis

Area of Science:

• Protein Biochemistry
• Structural Biology
• Thermostability Studies

Background:

• Understanding protein adaptation to extreme temperatures is crucial.
• Inter-residue contacts are key determinants of protein structure and function.
• Previous studies identified various factors influencing protein thermostability.

Purpose of the Study:

• To analyze inter-residue contacts in mesophilic and thermophilic proteins using all-atom potential energy.
• To correlate contact properties (number and energy) with protein thermostability.
• To identify novel contact types contributing to thermal adaptation.

Main Methods:

• Selection of 15 protein families with mesophilic and thermophilic representatives.
• All-atom potential energy calculations to define and analyze inter-residue contacts.
• Comparative analysis of contact numbers and energies between proteins from different thermal environments.

Main Results:

• Contact number and energy show stronger correlations with preferred protein temperatures than previously identified factors.
• Charged-polar and charged-nonpolar residue contacts exhibit higher contact numbers and lower energies.
• Thermophilic proteins possess a greater abundance of charged-polar and charged-nonpolar contacts compared to mesophilic counterparts.

Conclusions:

• Charged-polar and charged-nonpolar residue contacts play a significant role in protein thermostability.
• These interactions contribute to enhanced protein stability by strengthening the overall contact network.
• The findings suggest a broader role for charged residues in thermal adaptation than previously recognized.