Salt-bridge networks within globular and disordered proteins: characterizing trends for designable interactions

Area of Science:

• Biochemistry
• Structural Biology
• Protein Science

Background:

• Salt bridges are critical for protein structure and function, yet their exact role in stabilization is debated.
• These interactions involve charged amino acids and influence the activity-stability balance in proteins.

Purpose of the Study:

• To analyze the network modes of salt bridge association in globular proteins and at protein interfaces.
• To investigate the role of bifurcated salt bridges as a distinct motif in protein structure and interactions.
• To explore the contribution of salt bridges to the folding and stabilization of intrinsically disordered proteins.

Main Methods:

• Analysis of salt bridge networks within globular proteins.
• Characterization of salt bridges at protein-protein interfaces.
• Identification and analysis of bifurcated salt bridge motifs.

Main Results:

• Salt bridges contribute to the activity-stability trade-off by organizing charged amino acids.
• Bifurcated salt bridges are a common motif, acting as molecular clips to stabilize protein interfaces.
• Salt-bridge-mediated interactions are key in the partial folding and stabilization of disordered protein regions.

Conclusions:

• Bifurcated salt bridges are essential structural motifs with unique topological and geometric properties.
• These interactions play a vital role in promoting disorder-to-order transitions and stabilizing partially disordered proteins.
• Understanding salt bridge networks can guide the design of novel protein structures and elucidate the mechanisms of disordered proteins.