A Glimpse into the Initial Microsecond of Biomolecular Condensation

Area of Science:

• Biochemistry
• Molecular Biology
• Biophysics

Background:

• Biomolecular condensation is crucial for cellular function.
• The initial moments of phase transition during condensation are poorly understood.
• Intrinsically disordered proteins play significant roles in cellular processes.

Purpose of the Study:

• To investigate the molecular events and kinetics of peptide condensation within the first microsecond.
• To elucidate the mechanisms governing the ultrafast phase transition of biomolecules.

Main Methods:

• Temperature jump infrared spectroscopy was employed to probe rapid structural changes.
• Molecular dynamics simulations provided high-spatiotemporal resolution insights into the condensation process.

Main Results:

• Structural transitions and early assembly of intrinsically disordered proteins occur on ultrafast timescales.
• Backbone hydrogen bonding was identified as a critical factor stabilizing local structures during condensation, surpassing hydrophobicity's role.
• Hydrogen bonds facilitate the formation of stable interaction interfaces for assembly.

Conclusions:

• Hydrogen bonding is a key mediator in the ultrafast condensation of hydrophobic polypeptides.
• This mechanism enables disordered proteins to adopt preorganized conformations in response to stimuli.
• Hydrogen bonds are crucial for mediating assembly kinetics in cellular environments.