Fig. 6: Structural analysis of the differences in enzyme activity and stability before (1YKF) and after (7XY9) gelation.

a Overlay of the 7XY9 (salmon) and 1YKF (gray) structures. Inset shows the coordination of the Mg²⁺ ion with the adjacent residues. Dashed lines indicate the distances between the Mg²⁺ ion and coordination atoms of H102, C295, H157, and H100, which are equal to 2.2, 2.3, 2.0, and 2.4 Å, respectively. b RMSD values of 1YKF and 7XY9 obtained via high-temperature simulations. c DSC curves showing the thermostability of E, E_Hmtz, and EAG synthesized at different c(Mg²⁺) values. d Residual activities of the free enzyme and EAG measured after the exposure to an organic solvent (30% IPA or ACN, 2 h), thermal treatment (1 h), proteolytic agent treatment (trypsin, 3 h), and storage for 30 d. e Sliced surfaces of 1YKF (left) and 7XY9 (right). Black arrows indicate the substrate-binding pockets. f High-resolution Zn 2p XPS profiles of TbSADH, E_Mg, E_Hmtz, and EAG. g TS state determined for the hydride transfer step via DFT calculations. Representative snapshots of the conformational states obtained for h 1YKF and i 7XY9 via MD simulations. j Hydride transfer distance during MD simulations. k Specific activity and chiral selectivity values of the free enzyme and EAG catalyzing the conversion of AP with concentrations of 5–20 mM. Error bars represent the standard deviations from three independent experiments. For (d) and (k), n = 3. Data are expressed as the mean ± SEM. Source data are provided as a Source data file.