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High Activity and Convenient Ratio Control: DNA-Directed Coimmobilization of Multiple Enzymes on Multifunctionalized Magnetic Nanoparticles
journal contribution
posted on 2017-10-12, 00:00 authored by Ye Yang, Ruiqi Zhang, Bingnan Zhou, Jiayi Song, Ping Su, Yi YangThe development of new methods for
fabricating artificial multienzyme systems has attracted much interest
because of the potential applications and the urgent need for multienzyme
catalysts. Controlling the enzyme ratio is critical for improving
the cooperative enzymatic activity in multienzyme systems. Herein,
we introduce a versatile strategy for fabricating a multienzyme system
by coimmobilizing horseradish peroxidase (HRP) and glucose oxidase
(GOx) on magnetic nanoparticles multifunctionalized with dopamine
derivatives through DNA-directed immobilization. This multienzyme
system exhibited precise enzyme ratio control, high catalytic efficiency,
magnetic retrievability, and enhanced stability. The enzyme ratio
was conveniently adjusted, as required, by regulating the quantity
of functional groups on the multifunctionalized nanoparticles. The
optimal mole ratio of GOx/HRP was 2:1. The Michaelis constant Km and specificity constant (kcat/Km, where kcat is the catalytic rate constant) of the multienzyme
system were 1.41 mM and 5.02 s–1 mM–1, respectively, which were approximately twice the corresponding
values of free GOx&HRP. The increased bioactivity of the multienzyme
system was ascribed to the colocalization of the involved enzymes
and the promotion of DNA-directed immobilization. Given the wide variety
of possible enzyme associations and the high efficiency of this strategy,
we believe that this work provides a new route for the fabrication
of artificial multienzyme systems and can be extended for a wide range
of applications in diagnosis, biomedical devices, and biotechnology.