Microscale Colocalization of Cascade Enzymes Yields Activity Enhancement

Area of Science:

• Biochemistry
• Chemical Engineering
• Nanotechnology

Background:

• Enzyme colocalization is theorized to increase cascade reaction rates but lacks direct experimental validation.
• Challenges include controlling enzyme dispersion and quantifying colocalization effects accurately.
• Developing robust experimental systems is crucial for verifying these benefits.

Purpose of the Study:

• To experimentally evaluate the impact of enzyme colocalization on cascade reaction throughput.
• To establish a system for directly comparing colocalized and dispersed enzyme cascades under identical conditions.
• To investigate the underlying mechanisms and scale-dependent factors influencing colocalization enhancement.

Main Methods:

• Utilized reversible DNA-directed immobilization of enzymes onto microspheres.
• Established a model cascade system on highly dilute microspheres of specific sizes.
• Employed time-course analysis and reaction-diffusion modeling for quantification.

Main Results:

• Colocalized enzyme cascades exhibited enhanced activity, indicated by a shorter lag phase in product formation.
• Reaction-diffusion modeling identified intermediate substrate accumulation as a key factor for enhancement.
• The observed enhancement was dependent on the carrier size (microsphere size).

Conclusions:

• Direct experimental evidence confirms that enzyme colocalization boosts cascade reaction throughput.
• The colocalization effect is influenced by the interplay between nanoscale enzyme arrangement and microscale carrier size.
• Findings provide theoretical support for the rational design of efficient multienzyme catalysts.