Volumetric Strategy for Quantitatively Elucidating a Local Hydration Network around a G-Quadruplex

Area of Science:

• Biochemistry
• Molecular Biology
• Structural Biology

Background:

• Hydration is crucial for nucleic acid stability and molecular interactions.
• Quantitative understanding of hydration around specific nucleic acid structures like G-quadruplexes (G4) is needed.
• G4 structures are involved in various cellular functions and are targets for drug development.

Purpose of the Study:

• To quantitatively investigate the hydration properties of G-quadruplex (G4) RNA structures.
• To elucidate the volumetric changes associated with G4 RNA formation under varying G-quartet stacks and high pressure.
• To determine the hydration differences across various G4 structural components.

Main Methods:

• High-pressure experiments were employed to measure volumetric changes.
• Systematic variation of the number of G-quartet stacks in G4 RNA.
• Analysis of volumetric contributions at the level of individual G4 structural units.

Main Results:

• The core G4 helix was found to be significantly more dehydrated compared to other regions.
• Edges of G-quartets and loop regions exhibited different hydration levels than the core helix.
• Volumetric parameters were established for different G4 structural units.

Conclusions:

• The core G4 helix's dehydration is a key feature influencing molecular interactions.
• Findings aid in predicting G4 ligand binding based on ligand chemistry and solution conditions.
• The determined volumetric parameters can predict molecular interactions in G4 formations within cellular environments.