Pulsed electric fields induce modulation of protein liquid-liquid phase separation

Area of Science:

• Biophysics
• Materials Science
• Protein Crystallization

Background:

• Protein liquid dense clusters (LDCs) are crucial intermediates in protein crystallization.
• Understanding LDC assembly and structure is key to controlling crystallization processes.
• External fields can potentially influence biomolecular phase transitions.

Purpose of the Study:

• To investigate the effect of pulsed electric fields (EFs) on the dynamic assembly and structure of protein LDCs.
• To explore how EFs modulate the phase diagrams of LDC formation and protein crystallization.
• To understand the structural changes in proteins and LDCs induced by EFs.

Main Methods:

• Time-resolved dynamic light scattering (DLS/DDLS)
• Optical microscopy
• Transmission electron microscopy (TEM)
• Circular dichroism (CD) spectroscopy

Main Results:

• Pulsed EFs significantly altered the morphology and spatial distribution of protein LDCs and microcrystals.
• EFs enabled protein solutions to overcome phase separation barriers, modifying LDC formation phase diagrams.
• LDCs were identified as precursors to protein crystal nuclei, with pulsed EFs promoting ordered structure formation within LDCs.
• EFs induced changes in protein secondary structure, impacting protein-protein interactions and LDC characteristics.
• EFs demonstrated control over protein LDC and microcrystal morphology, dimensions, and internal structure.

Conclusions:

• Pulsed EFs offer a method to modulate protein crystallization phase diagrams.
• EFs can control the physical morphology and internal structure of protein LDCs and microcrystals.
• This provides a novel approach for manipulating protein self-assembly and crystallization processes.