Direct intracellular detection of biomolecule specific bound-water with Raman spectroscopy

Area of Science:

• Biophysics
• Biochemistry
• Spectroscopy

Background:

• Biomolecules like lipids, proteins, and nucleic acids interact with water molecules, forming a hydration shell.
• This 'bound water' exhibits distinct physical properties compared to bulk water.
• Understanding intracellular water is crucial for comprehending biomolecular function.

Purpose of the Study:

• To investigate the potential of Raman imaging for resolving the specific hydration shell of biomolecules within cells.
• To differentiate the spectral characteristics of water associated with lipids and proteins/nucleic acids from bulk water.

Main Methods:

• Utilized Raman imaging to acquire spectral data from intracellular regions.
• Analyzed Raman spectra to resolve components associated with lipids and proteins/nucleic acids.
• Compared the spectral features of intracellular bound water with those of bulk water and hydrated pure biomolecules.

Main Results:

• Successfully resolved distinct Raman spectral components for lipids and proteins/nucleic acids.
• Identified unique spectral features of associated water (bound water) in intracellular biomolecules.
• Observed that these bound water spectral profiles differ significantly from bulk water.
• Validated findings by comparing with spectra of hydrated pure biomolecules.

Conclusions:

• Raman imaging is a promising technique for studying intracellular hydration shells.
• The study demonstrates the ability to differentiate bound water from bulk water in biological systems.
• Findings highlight the functional relevance of specific water-biomolecule interactions within cells.