Fig.8
3.8 Kinetic study of enzyme
Kinetic parameters of the free
enzyme and immobilized enzyme were determined with phenylpyruvate
concentrations ranging from 1.25 to 15.00 mM. Kinetic parameters were
calculated based on the Michaelis‐Menten equation. The Michaelis
constants were calculated and showed (Table 1). Comparing with free
enzyme, the Km value of immobilized enzyme decreased,
which indicated that the improvement of the affinity between enzyme
(DAADH) and the substrate (Phenylpyruvate).
Vmax/Km of DAADH/ZIF-8/RGO and
DAADH/ZIF-8 were 1.3 and 1.6-fold of the free enzymes, respectively. The
enhancement of kinetic parameters probably because ZIF-8’s and
ZIF-8/RGO’s pore and inner-surface with functionality variations
optimize the interior environment, which was beneficial to facilitate
the substrate’s diffusion [28].