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Biomedical subjects

Baoquan Ding

Publications and source records attributed to Baoquan Ding.

3 recordsLinked to original sources

Operation of a DNA robot arm inserted into a 2D DNA crystalline substrate.

The success of nanorobotics requires the precise placement and subsequent operation of specific nanomechanical devices at particular locations. The structural programmability of DNA makes it a particularly attractive system for nanorobotics. We have developed a cassette that enables the placement of a robust, sequence-dependent DNA robot arm within a two-dimensional (2D) crystalline DNA array. The cassette contains the device, an attachment site, and a reporter of state. We used atomic force microscopy to demonstrate that the rotary device is fully functional after insertion. Thus, a nanomechanical device can operate within a fixed frame of reference.

Crystallization↗

Double cohesion in structural DNA nanotechnology.

Double cohesion has proved to be a useful tool to assemble robust 2D arrays of large tiles. Here we present a variety of examples showing the utility of this approach. We apply this principle to the 3 types of 2D lattice sections of arrays whose individual tiles are inherently 3 dimensional, because they contain three vectors that span 3-space. This application includes motifs which are based on the tensegrity triangle, the six-helix bundle motif and on three skewed triple crossover molecules. All of these designs have the potential to form 3 dimensional structures if all three directions of propagation are allowed. If one direction is blunted, 2D arrays form, and all 3 combinations are presented here. In addition, a large parallelogram array that was not attainable previously using single duplex cohesion was also constructed using double cohesion. For comparison, arrays which use another type of double cohesion, double paranemic (PX) cohesion are also presented. Double cohesion of sticky ends proved to be the more effective tool to assemble large motifs into arrays.

DNA↗

Pseudohexagonal 2D DNA crystals from double crossover cohesion.

Two-dimensional pseudohexagonal trigonal arrays have been constructed by self-assembly from DNA. The motif used is a bulged-junction DNA triangle whose edges and extensions are DNA double crossover (DX) molecules, rather than conventional DNA double helices. Experiments were performed to establish whether the success of this system results from the added stiffness of DX molecules or the presence of two sticky ends at the terminus of each edge. Removal of one sticky end precludes lattice formation, suggesting that it is the double sticky end that is the primary factor enabling lattice formation.

Crystallization↗