DNA a modifiable toolAbstract: DNA has many bonding capabilities that allow this molecule to form “machines”.These structures are created by the interactions of different DNA sequences that help inthe process of synthesis and even in the process of gene silencing. Another templateused in the synthesis of these macromolecular structures is branched DNA or bDNA,which later leaves the option of simply bonding bDNA to synthesize lattices, or otherstructures (Teller et. al 2010). Uridine is also used to synthesize bDNA (Chandra et. al2007). Another way to unite two strands of DNA is by the integration of oligomers(Dolinnaya et. al 2001). Bonding can be assured, by observing changes in fluorescence.It is given off as energy after applying a special dye that allows the light to be viewed(Yurke et.al 2000). DNAzymes are oligomers that are used to silence genes (Dass et. al2008). This process can help with the eradication of hereditary diseases.Introduction: DNA is an astonishing molecule representative of the continuity and diversification of organisms. Continuity is represented, because during cell division, the molecule is alsoreplicated to continue playing a major role in protein synthesis necessary for the survival and development of species. Diversification is represented, because when it comes to reproduction, gametes produced by meiosis contain different combinations of parent DNA. Not only is the DNA structure; the double helix, made for its own synthesis, but now itis integrated into the investigation of nanotechnology. Some properties of the molecule, such as the bonding of nucleotide sequences, and the nucleotides themselves, add tothe list of things DNA is capable of doing. Furthermore, DNA is being bonded to itself to create structures that can function according to the shape of the structures. other types of structures. DNAzymes are DNA structures that serve asBinding DNA: catalysts in reactions. They are created due to specific conditions that bind the DNA comes with instructions for all of molecules in certain places to createits major processes. Researchers (Teller shapes. As authors indicate, structureet. al 2010) show that certain nucleotide determines the function of the molecule.sequences serve as a locator for bindingsites. Here, crossing over occurs, similar Bonding is also possible due to certainto the differentiation process in meiosis. ending sequences or telomeres thatIonic bonds also occur due to polarity in have a sticky characteristic. Literallythe molecule that promotes shaping to DNA sequences are cut and bonded by these ends to create the nanostructure made from DNA. Depending on the type of bond, the difficulty of structuring is equally proportional. If the bond is dependent on
charges, sequences that have the uracil and the sugar ribose in theopposite charge have to be located. backbone of the DNA molecule formingThis causes these opposite charges to this glycosidic linkage. Other DNAattract to form a bond, and subsequently molecules can be added to thesea shape. linkages to create new branches to the original structure. This results in the They further indicate that when DNA is formation of bDNA.exposed to a magnetic field, it reacts bycurling and bending itself, by the Structures Made from DNA andrepulsive and attractive forces. After the their applications:magnetic field is either removed or shutdown, the molecule had reacted to The shorter the structure, the strongerthese fields. It ends up all curled and it will be. This is why nanotechnology isbonded with its own backbone; it being incorporated into manybecomes adhered this way, forming a investigations today.very strong structure. Tweezer shaped DNA is used for Furthermore, shapes like tweezers ultrasensitive sensing. The reactions thefrom DNA can be created. Lattices can molecules have when exposed to eitherbe synthesized by the bonding of many polar fields can help determine themolecules of bDNA. Another way that environment. When DNA molecules areDNA is applied to nanotechnological exposed to an environment with varyingresearch is the incorporation of pH, the reaction can be recorded andDNAzymes. This involves the usage of analyzed. The results can be used tothe oligomers, or single stranded DNA determine how DNA reacts to theseto take part in the process of gene changes in pH. These are called DNAsilencing. machines. These molecular machines are stimulated to open and close by the Branching in DNA called bDNA, addition of DNA molecules. Thisoccurs naturally. Bonding these process is called hybridization (Yurkemolecules is possible with the use of et.al 2000). A dye that emitssingle stranded DNA fragments called fluorescence is added so it can later beoligomers. Water soluble reagents are quantified. In this case, fluorescence isused to ligate the oligomers to bDNA measured as a form of energy released.(Dolinnaya et. al 2001). Branched DNA A proportion was established becauseis more efficiently bonded by the use of when the level of fluorescence is high,double stranded oligomers. They are the “tweezers” are closed, on thebonded by their phosphate backbone, in contrary, if these levels are low, then thean overlapping pattern, with a “locking in molecules is said to be opened. Whenplace bond” to the other DNA strands. there is opening of the tweezers, energyThis procedure is a type of chemical is being used up, so there is evidence ofligation. a reaction occurring. However, bDNA can also be DNAzymes are types of DNA thatsynthesized more efficiently with the catalyze chemical reactions (Dass et. alintegration of uridine (Chandra et. al 2008). They can function as enzymes,2007). Uridine is a branching monomer acquiring the denomination. They arethat is created by the combination of introduced into a cell to then be
transported into the nucleus. Most some molecules that once they take partDNAzymes are light activated. They in the process, they stimulate thebecome active in terms of mobility inside activation of others to completelythe nucleus. DNAzymes catalyze a replicate a DNA molecule. However,specific synthesis of DNA by cleaving the phenomenon of bDNA occursinto RNA and causing gene silencing. In naturally with the bonding of the stickythis way the origin of a genetic disease ends with another strand of DNA.is eradicated by simply eliminating acertain gene or causing the synthesis of Oligomers or single stranded DNA areanother. This process requires the extracted as DNA replication takesintegration of oligomers, that bond to place. These oligomers also occurtheir corresponding RNA sequences naturally but require the process ofand silences the gene (Dass et. al extraction.2008). DNA nanotubes are a combination ofa DNA molecule wrapped around acarbon nanotube. This structure canthen be applied for sensing ofcomplimentary DNA. When bonding ofthe complimentary strand occurs to thestrand in the carbon nanotube, thefluorescence is altered giving off areading that confirms bonding is takingplace between oligomers.DNA lattices are used to enclosematerials. This combination can addmagnetism and even increase or evenadd efficiency to the material’s catalyticproperties. These lattices can also beused as cell compartments. Cellsadhere to the molecular structures,where they can be studied or observedand are Perfect for “In Vitro ” testing.The environment can be controlled byadding substances that react to maintaindesired conditions. As these cellsreplicate, they are contained in theselattices for further studies.Replication of the Structures: The replication of the tweezer likeDNA, and the lattice composed of DNAhas not yet been achieved perhapsbecause DNA is replicated in a specificprocess that requires the integration of
Conclusions: The integration of DNA to nanotechnology enhances the nanotechnology that alreadyexists. The example of the wrapping of the DNA strand to detect complimentary strandsserves as an application for carbon nanotubes. DNA machines are also a great example of nanotechnological advances and can be applied to many tests and experiments. Oligomers can silence genes, meaning that the expression of a disease can be silenced. This can lead to the elimination of possible hereditary diseases that might beexpressed. For example, for a tumor to start, it needs epithelial proteins, that help these masses adhere. The single stranded DNA can be used to silence the gene that can be translated into this protein, thus avoiding adherence of the tumors. Another possible application of these DNA machines can be on lab testing. Changes in pH or other factors can affect the structure of DNA. Lab tests can be revised and these factors can be observed to help determine their healthy levels in the blood serum. This can help maintain the structure of DNA and maybe avoid the damaging of it. This damaging ofthe structure might lead to wrongful synthesis of certain proteins, thus causing diseases or even mutations.
References: 1.Chandra Madhavaiah, Keller Sascha, Luo Yan and Marx Andreas. 2007. A modified Uridine for thesynthesis of branched DNA, Tetrahedron. Volume 63, issue 35: pages 8576-8580. 2.Dass Crispin R., Choong Peter F.M. and Khachigian Levon M., DNAzyme technology and cancertherapy: cleave and let die, Department of Orthopedics, St. Vincent’s Hospital Melbourne, Fitzroy, Victoria,Australia; Bone and Soft Tissue Sarcoma Service, Peter MacCallum Cancer Centre, Melbourne, Australia;and Centre for Vascular Research, Department of Pathology, School of Medical Sciences, The University ofNew South Wales and Department of Hematology, Prince of Wales Hospital, Sydney, Australia. 3.Dolinnaya Nina, Gryaznov Sergei, Ahle David, Chang Chu-An, Shabarova Zoe A., Ureda Mickey S. andHorn Thomas, 2001. Construction of branched DNA (bDNA) molecules by chemical ligation, LynxPharmaceuticals, Foster City, CA 94404, USA. 4. Teller Carsten and Willner Itamar. 2010. Functional nucleic acid nanostructures and DNA machines,Institute of Chemistry, the Hebrew University of Jerusalem, 91904 Jerusalem, Israel. 5.Yurke Bernard, Turbereld Andrew J., Mills Allen P. Jr , Simmel Friedrich C. & Neumann Jennifer L., ADNA-fuelled molecular machine made of DNA, Bell Laboratories, Lucent Technologies, 600 MountainAvenue, Murray Hill, New Jersey 07974, USA Department of Physics, University of Oxford, ClarendonLaboratory, Parks Road, Oxford OX1 3PU, UK. 6.Science Direct- investigation listings, PDF 7.Nature- magazine 8.Proquest- Website