Biocatalytic Activity and Energetics of Immobilized Bovine Carbonic Anhydrase On Mesostructured Cellular Foam Silica

Carbonic anhydrase is an enzyme that catalyzes the hydration and dissociation of carbon dioxide, a greenhouse gas, to bicarbonate under mild conditions; this reaction can be used for CO₂ sequestration. Due to its reaction specificity, carbonic anhydrase can be an energy-effective biocatalyst for CO₂ mitigation. In this study, bovine carbonic anhydrase is immobilized on native and functionalized mesostructured cellular foam (MCF) silica, which has an ordered three-dimensional pore structure with high porosity and high surface area, to investigate the effect of surface modification on catalytic activity (k_cat, k_cat/K_m). The heat of immobilization (ΔH) is measured by flow microcalorimetry (FMC) to elucidate the fundamental interactions between bovine carbonic anhydrase and the mesoporous host. The FMC data provide invaluable insight allowing optimization of surface properties of mesoporous silica host to produce highly efficient immobilized carbonic anhydrase systems.