Docstoc

DNA - Download as PDF

Document Sample
DNA - Download as PDF Powered By Docstoc
					
				
DOCUMENT INFO
Description: This disclosure relates generally to methods, kits and compositions pertaining to molecular switches. The disclosure also relates to nanoscale DNA architectures that comprise molecular switches.BACKGROUND The following description is provided to assist the understanding of the reader. None of the information provided or references cited is admitted to be prior art. One aim of biotechnology and nanotechnology is a rational approach to the construction of new biomaterials, including individual objects and nanomechanical devices. Intricate arrangements of atoms could serve many practical purposes. Theinformational macromolecules of biological systems, proteins and nucleic acids, are believed to have the potential to serve as building blocks for these constructions, because they are used for similar purposes in the cell. Structural DNA nanotechnologyis an emerging field that uses DNA to create either rigid architectures or dynamic switches. Dynamic, DNA-based nanodevices may also be described as molecular switches. They are based on structural transitions between two well-defined conformations ofDNA upon the application of a stimulus. For instance, nanometer-scale circuitry and robotics could accomplish many tasks that are impossible today. One can envision improvements in the storage and retrieval of information, understanding of themolecular basis of medical problems, and the assembly of very smart materials as possible end products of the ability to control the structure of matter on the nanometer scale.SUMMARY The compositions and methods described herein are based on the discovery that a parallel-stranded double helix of poly dA nucleic acid or "A-motif" shows reversible changes in conformation in response to pH. DNA strands can be hybridized on cuewith a pH change and melted on cue with another pH change. Thus, the A-motif may be used in nanoscale DNA architectures that can self-assemble and dis-assemble on externally added pH cues. In one aspect, the