Metal-Catalyzed Hydrolysis of RNA in Aqueous Environments

Area of Science:

• Environmental chemistry
• Molecular biology
• Biochemistry

Background:

• RNA stability is crucial for environmental applications like pesticide fate assessment and wastewater-based epidemiology.
• Abiotic reactions, particularly metal-catalyzed hydrolysis, can contribute to RNA degradation.
• Previous studies show metals accelerate RNA hydrolysis at elevated temperatures and higher concentrations.

Purpose of the Study:

• To investigate metal-catalyzed RNA hydrolysis under environmentally relevant conditions.
• To determine the influence of metal Lewis acidity and RNA structure on hydrolysis rates.
• To assess the impact of environmental factors on RNA stability in aqueous systems.

Main Methods:

• Assessing RNA hydrolysis rates under varying conditions (temperature, pH, metal concentration, ligands).
• Comparing the susceptibility of single-stranded RNA (ssRNA) and double-stranded RNA (dsRNA) to metal catalysis.
• Evaluating the role of metal Lewis acidity (e.g., lead, copper, zinc, nickel) in RNA degradation.

Main Results:

• At ambient temperature, neutral pH, and low metal concentrations (∼10 μM), strong Lewis acid metals (lead, copper) catalyzed ssRNA hydrolysis.
• Weaker Lewis acid metals (zinc, nickel) did not catalyze ssRNA hydrolysis under these conditions.
• Double-stranded RNA (dsRNA) demonstrated resistance to hydrolysis by all tested metals.
• Lowering pH and adding ligands significantly reduced metal-catalyzed ssRNA hydrolysis rates.

Conclusions:

• Under typical environmental conditions (sub-micromolar metal concentrations, ambient temperature, neutral pH), significant metal-catalyzed hydrolysis of both ssRNA and dsRNA is unlikely.
• RNA structure (ssRNA vs. dsRNA) and environmental factors play critical roles in determining RNA stability.
• This study provides crucial insights for interpreting RNA data in environmental monitoring and wastewater epidemiology.