On-Origami Molecular Crowding Control of G-Quadruplex DNAzymes

The proper crowding of biomacromolecules in cytoplasm and on cell surfaces plays a critical role in cell morphology and metabolism regulations. It is also important to optimize the crowding of target molecules at optimal density on artificial interfaces to perform the best activities, which remains a challenge. Here, DNA origami is employed as a precise template to regulate the placing density and crowding of a model DNAzyme, the G-quadruplex (G4)-hemin complex, achieving high catalytic efficiency at moderate crowding. As crowding increases, DNAzyme is susceptible to inactivation, leading to a decrease in catalytic performance. As the location template, DNA origami is shown to be an isotropic scaffold and can be constructed to form nanoenzyme ensembles with variable catalytic efficiencies under moderately crowded conditions. DNA origami and G4-hemin DNAzyme are utilized to design a mechanochemical sensor and accomplish the detection of the disease target Human Papillomavirus (HPV)-16 DNA fragment.