Intracellular biomolecular condensates viewed by Raman microscopy: Composition, crowding, and hydration

Area of Science:

• Biochemistry and Molecular Biology
• Cell Biology
• Biophysics

Background:

• Liquid-liquid phase separation (LLPS) drives the formation of biomolecular liquid droplets, essential for various intracellular processes.
• These droplets contain proteins, coexisting components, and hydration water, with properties influenced by internal composition and cellular environment.
• Quantitative understanding of these factors within living cells is limited.

Purpose of the Study:

• To review recent advancements in using Raman microscopy to study intracellular droplets.
• To highlight the role of Raman microscopy in analyzing droplet composition, hydration, and molecular crowding.
• To explore the relationship between droplet properties and the intracellular environment.

Main Methods:

• Label-free Raman microscopy for direct analysis of intracellular droplets.
• Quantitative measurement of constituent molecules and hydration water concentrations.
• Assessment of intracellular molecular crowding environments.

Main Results:

• Raman microscopy enables label-free characterization of intracellular droplet structures and molecular concentrations.
• The technique provides insights into the abundance of hydration water within droplets.
• Studies reveal correlations between droplet characteristics and molecular crowding in the cellular milieu.

Conclusions:

• Raman microscopy is a powerful tool for investigating the complex interplay of factors governing intracellular droplets.
• Understanding droplet composition, hydration, and crowding is key to deciphering their biological roles.
• This review consolidates current knowledge on Raman-based studies of biomolecular condensates.