Immobilization of Kluyveromyces lactis β‐Galactosidase on Meso‐macroporous Silica: Use of Infrared Spectroscopy to Rationalize the Catalytic Efficiency

Enzyme immobilization on adequate carriers is a challenging strategy. Understanding the enzyme‐carrier interactions and their effects on enzyme conformation and bioactivity is critical. In this study, a meso‐macropores silica (MMS) was used to immobilize β‐galactosidase from the yeast Kluyveromyces lactis (β‐gal‐KL) by physical adsorption. The bioactivity of the immobilized β‐gal‐KL was altered, evidenced by the increased K(m), decreased V(max) and k(cat), and increased activity at alkaline values. By performing infrared spectroscopy analysis and subsequent secondary structure assessment from the amide I band, the immobilized β‐gal‐KL suffered a β‐sheet (∼31–35 %) to α‐helix (∼15–19 %) transition with increased turns (∼21–22 %) with respect to the free β‐gal‐KL having ∼12 % α‐helix, ∼42 % β‐sheet, and ∼17 % turns. These findings led us to correlate the observed bioactivity performance to structural alterations to a non‐native conformation. The presented line of thought can lead to a better understanding of the reasons causing bioactivity alterations upon enzyme immobilization.