A direct electrode-driven P450 cycle for biocatalysis

Area of Science:

• Biocatalysis and Enzyme Engineering
• Electrochemical Synthesis
• Organic Chemistry

Background:

• Redox enzymes offer significant potential for synthesizing high-value organic compounds.
• Efficient cofactor regeneration is crucial for the economic viability of biocatalytic processes.
• Current cofactor regeneration methods often face limitations in scalability and efficiency.

Purpose of the Study:

• To develop an innovative bioreactor for direct cofactor regeneration in redox enzyme systems.
• To investigate the direct electrochemical supply of reducing power to cytochrome P450cam (CYP101).
• To achieve sustained and efficient biocatalysis using an integrated electrochemical-enzymatic system.

Main Methods:

• A bioreactor was designed utilizing an antimony-doped tin oxide electrode for direct electron transfer to putidaredoxin, the redox partner of CYP101.
• Oxygen, essential for the catalytic cycle, was generated electrochemically via water electrolysis at a platinum counter electrode.
• The system employed purified cytochrome P450cam (P450cam) for the biocatalytic transformation.

Main Results:

• A continuous catalytic cycle was successfully sustained for over 5 hours.
• The system achieved more than 2,600 enzyme turnovers, demonstrating high operational stability.
• A maximum product formation rate of 36 nmol of 5-exo-hydroxycamphor/nmol of CYP101 per minute was recorded.

Conclusions:

• Direct electrochemical regeneration of cofactors is a viable and efficient strategy for powering redox enzymes.
• This integrated electrochemical-enzymatic approach offers a promising platform for sustainable and scalable biocatalysis.
• The developed bioreactor system significantly enhances the efficiency and turnover of cytochrome P450cam-mediated reactions.