Broadening the Scope of Biocatalysis Engineering by Tailoring Enzyme Microenvironment: A Review

The rational design of catalysts that fine-tune/mimics the enzyme microenvironment remains the subject of supreme interest. Several strategies moving from traditional to technologically advanced methods have been proposed and deployed to develop high efficacy enzymes. There is a plethora of literature on simple enzyme immobilization through different materials as support carriers, even at the micro- and nanoscale. Regardless of extensive strategic efforts, the existing literature lacks deep insight into tailoring the microenvironment surrounding the target enzyme molecules and can sophisticatedly integrate the bio-catalysis for multipurpose applications. The ongoing advancement in the industrial sector also demands catalysts with unique features. For instance, catalytic turnover, substrate affinity, stability, specificity, selectivity, resistivity against reaction impurities or inhibitors, prevention of subunit dissociation, ease in recovery, and reusability are highly requisite features. This review spotlight state-of-the-art protein engineering approaches that facilitate the redesigning of robust catalysts or fine-tuning the catalytic microenvironment of enzymes. The entire work critically focuses on protein engineering approaches, i.e., regulating pH microenvironment, creating a water-like microenvironment, activating enzyme catalysis in organic solvents and gas phase, tuning reaction kinetics (K_M and k_cat), engineering substrate specificity, reaction promiscuity, computational design, and structure-guided biocatalyst engineering. This study unveils the advanced insights of enzyme microenvironment engineering, which can also be considered catalytic yield enhancement strategies to green the future bio-catalysis research for industrial bioprocesses. Graphical abstract: [Figure not available: see fulltext.]