Lattice-Like DNA Tetrahedron Nanostructure as Scaffold to Locate GOx and HRP Enzymes for Highly Efficient Enzyme Cascade Reaction.

In this work, the array arrangement of cascade enzymes was implemented by alternately and equidistantly anchoring two model enzymes glucose oxidase (GOx) and horseradish peroxidase (HRP) to the vertexes of rigid DNA tetrahedron units in lattice-like nucleic acid scaffold, in which the distance between any adjacent cascade enzymes had been regulated to the optimum for obtaining high enzyme cascade catalytic efficiency. Compared to the enzyme cascade system with no-array arrangement of cascade enzymes, the proposed enzyme cascade system allowed the intermediate H2O2 produced by GOx catalyzing substrate glucose to concurrently and equidistantly diffuse toward the four adjacent HRP enzyme surfaces. In this case, the invalid diffusion effect of intermediate H2O2 between cascade enzymes could be effectively avoided, thereby promoting the enzyme cascade reaction with high catalytic efficiency. The specific catalytic efficiency (kcat/Km) of the cascade enzyme system with array arrangement had been evaluated, which exhibited catalytic efficiency about 3.6 times higher than that of the randomly arranged cascade enzyme system. As a result, this strategy provided a new avenue for constructing a highly efficient enzyme cascade system with ultimate applications in biosynthesis, bioanalysis, and biodiagnostics.