Enzymatic oxygen scavenging for photostability without pH drop in single-molecule experiments

Area of Science:

• Bionanotechnology
• Biochemistry
• Biophysics

Background:

• Bottom-up bionanotechnology relies on single-molecule techniques requiring anaerobic conditions.
• Common oxygen scavengers like glucose oxidase/catalase (GOC) and protocatechuate dioxygenase (PCD) produce carboxylic acids, causing pH drops.
• Existing methods necessitate high buffer strength to counteract pH instability during experiments.

Purpose of the Study:

• To introduce a novel enzymatic oxygen-scavenging system for pH-stable single-molecule experiments.
• To evaluate the performance of the pyranose oxidase and catalase (POC) system compared to existing methods.
• To demonstrate the utility of POC for extended observation of bionanotechnological assemblies.

Main Methods:

• Development and implementation of the pyranose oxidase and catalase (POC) enzymatic system.
• Monitoring of pH stability over time using POC, GOC, and PCD systems.
• Single-molecule fluorescence experiments to assess the performance of POC under various buffer conditions.

Main Results:

• The POC system maintained stable pH for extended periods (hours).
• GOC and PCD systems exhibited significant pH drops due to carboxylic acid production.
• POC demonstrated comparable performance to GOC and PCD in single-molecule fluorescence experiments.
• POC offers greater flexibility in buffer conditions and long-term pH stability.

Conclusions:

• Pyranose oxidase and catalase (POC) is a superior oxygen-scavenging system for single-molecule experiments requiring pH stability.
• POC enables longer and more reliable observations of bionanotechnological assemblies in aqueous environments.
• This system provides researchers with enhanced freedom in experimental design and buffer optimization.