Microenvironmental effects can masquerade as substrate channelling in cascade biocatalysis

Area of Science:

• Biocatalysis and enzyme engineering
• Biochemical engineering
• Molecular biology

Background:

• Natural enzyme cascades utilize spatial organization for substrate channeling, enhancing catalytic efficiency.
• Engineered multienzyme cascades mimic this spatial organization to improve catalysis.
• Molecular scaffolds enable spatial organization but can alter the enzyme microenvironment.

Purpose of the Study:

• To review the effects of microenvironment on enzyme activity and cascade kinetics.
• To discuss examples of microenvironment exploitation for improved catalysis.
• To highlight challenges in attributing kinetic enhancements solely to substrate channeling.

Main Methods:

• Literature review of enzyme immobilization and microenvironment effects.
• Analysis of engineered multienzyme cascade studies.
• Case study examination of microenvironment-mediated catalysis.

Main Results:

• The microenvironment significantly impacts enzyme activity, independent of substrate channeling.
• Scaffolds used for spatial organization can create distinct microenvironments.
• Distinguishing microenvironment effects from substrate channeling benefits is challenging.

Conclusions:

• Understanding microenvironment effects is crucial for accurate kinetic analysis of engineered cascades.
• Exploiting microenvironment properties can enhance both single enzyme and cascade catalysis.
• Further research is needed to decouple microenvironment influences from substrate channeling in engineered systems.