Unraveling Structural Changes and the Reaction Mechanism in Urease upon Infrared Physical Inactivation

To improve energy efficiency and inhibit urease, this study developed an infrared physical field (IPF) method. This study integrates experimental approaches and computational simulations to elucidate the mechanism of urease inactivation under IPF treatment. The optimal treatment (130 °C-9 min) reduced the enzyme activity by 97.55% within the experimental range (90-130 °C, 1-9 min). Experimentally, circular dichroism showed a 25.36% increase in random coil content, and hydrophobicity assays showed a 1.23-fold increase in surface hydrophobicity. Molecular dynamics simulations predicted disruption of intra- and intermolecular hydrogen bonds (2.60% and 11.69%), van der Waals interactions (99.99%), and electrostatic interactions (96.80%). The computed ΔG_bind became 98.98% more negative, matching the experimental 99.36-fold reduction in K_cat/K_m. In summary, IPF at 130 °C-9 min effectively inactivated urease via significant disruption of conformational structures and catalytic function.