Modulation of Coiled-Coil Dimer Stability through Surface Residues while Preserving Pairing Specificity.

Area of Science:

• Protein engineering
• Structural biology
• Nanotechnology

Background:

• Coiled-coil dimers are common protein structures and versatile building blocks for nanostructures.
• Dimer specificity relies on hydrophobic and electrostatic interactions at specific residue positions.
• Stability can be influenced by residues outside the direct dimerization interface.

Purpose of the Study:

• To demonstrate a method for tuning coiled-coil dimer stability by engineering local helical propensity.
• To show that stability can be modulated without changing peptide length or directly interacting residues.
• To provide a general principle applicable to various coiled-coil systems.

Main Methods:

• Designing intramolecular charge pairs to create trigger sequences.
• Engineering regions of high local helical propensity in peptides.
• Analyzing changes in thermal stability and binding preferences.

Main Results:

• Stability of coiled-coil dimers was tuned over a wide range, with a >30 °C change in thermal stability observed.
• Two mutations outside the binding interface significantly altered dimer stability.
• The approach successfully modulated stability in an orthogonal set of coiled-coils without affecting binding preferences.
• A simple linear model accurately describes the stability effects of local helical propensity and peptide charge.

Conclusions:

• Engineering local helical propensity is an effective strategy for tuning coiled-coil dimer stability.
• This method offers precise control over stability for applications in synthetic biology and nanomaterials.
• The findings can improve predictive algorithms for coiled-coil stability.