Material Detail

A switchable imitating DNA-packaging motor was constructed in the laboratory. The motor is driven by six synthetic ATP-binding pRNA (packaging RNA) molecules that bind to the connector and function in a manner similar to the driving of a bolt with a hex nut. Conformational change and sequential action of the RNA ensure continuous rotation of the motor, with ATP as energy. A 5-um DNA was packaged using this synthetic motor using one ATP to translocate two base pairs of DNA. The DNA-filled capsids were subsequently converted into infectious virus. Direct observation revealed that the motor can tow a bead more than 500 nm. The 3D structures of pRNA/motor complex and the pRNA monomer, dimer and hexamer have been probed by photo affinity crosslinking, chemical modification interference, nuclease probing, cryo-AFM and computer modeling. pRNA's size and shape can be controlled and manipulated at will to form stable dimers, trimers and arrays for nanotechnological applications. The motor can be turned off and turned on again. The formation of ordered structural arrays of the motor complex and its components and the ease of RNA dimer, trimer, and hexamer manipulation with desired shape and size make this motor system a promising tool for use as building block for nanodevice and/or for gene delivery. Efficient inhibition of the growth of cancer or cancer cell was demonstrated in cell cultures or animal models through the use of motor nanoparticle to deliver therapeutic siRNAs and/or ribozymes to breast cancer cells, human oropharyngeal epidermoid carcinoma KB cells, leukemia model T cells, lung cancer cells, or hepatitis B virus-infected cells.

Disciplines:

• Science and Technology  / Nanotechnology