Fig. 3: Assembling mechanism of laccase on Cellulose-CD-MMT hydrogels via CAHB.
From: Advanced enzyme-assembled hydrogels for the remediation of contaminated water
a The relationship between assembled amount of laccase on Cellulose-CD-MMT hydrogels and solution pH. The solution pH before and after laccase assembly showed that it significantly and linearly increased with increasing assembled amount of laccase (p < 0.05). b Schematic diagram of the proposed CAHB interaction between laccase and Cellulose-CD-MMT hydrogels. FTIR (c) and 1H NMR (d) spectra of laccase before and after assembly (including deuteration) on Cellulose-CD-MMT hydrogels. Initial state (e, 0 ns) and equilibrium state (f, 100 ns) of the interaction between Cellulose-CD-MMT hydrogels and laccase by molecular dynamics (MD) simulation. The cyan box is a cube water box of 10 × 10 × 10 nm. g Contribution of different amino acids to H-bond formation between laccase and Cellulose-CD-MMT hydrogels within 100 ns MD simulation. Aspartic acid: Asp (75.02%), Arginine: Arg (9.07%), Histidine: His (10.64%), Serine: Ser (2.54%), Leucine: Leu (1.18%), Glutamine: Gln (0.91%), Proline: Pro (0.04%). Strength (h, EH-bond, kJ mol−1) and stability (i, Egap, eV) of the H-bond between Cellulose-CD-MMT hydrogels and Asp quantified through DFT calculation. The representative H-bond conformation is obtained by MD simulation at 100 ns. A shorter bond length with larger bond angle and binding energy means a stronger H-bond. EHOMO and ELUMO are the energy (eV) of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), respectively.
