Monday, 16 April 2012

DNA binding molecule

Student number: 42939883
TM George

University of Texas Scientists discover DNA binding molecule


The University of Texas at Austin in the USA has put out a message on February 12 2012 detailing their discovery of a new molecule that has the potential to immobilise genes that play a part in diseases such as HIV, cancer and also in genetic diseases. The study, which was released in Nature Chemistry in September of 2011 holds great promise in the future of treatment for these conditions.

Brent Iverson, the chair of the department of chemistry at the university announced that the molecule could intertwine itself into the DNA double helix and render it incapacitated for up to sixteen days. He likened the molecule to a block in a spiral staircase that is the DNA double helix, stating that,

If you think of DNA as a spiral staircase, imagine sliding something between the steps. That's what our molecule does. It can be visualized as binding to DNA in the same way a snake might climb a ladder. It goes back and forth through the central staircase with sections of it between the steps. Once in, it takes a long time to get loose. (Iverson, B., 2012)


Figure 1: A diagram of how the molecule bonds to a segment of DNA (The University of Texas 2012)


The molecule is particularly promising in the field of HIV treatment. HIV begins as a viral infection. The virus inserts into a cell RNA and other enzymes, giving it the ability to infiltrate into the genetic DNA of the cell. Some forms of cancer also infiltrate the genetic DNA of the cell, via a random or environmentally influenced mutation rather than a virus. This DNA is then reproduced along with the original DNA in the person’s cells at a staggering rate (Wilkins 2012). The DNA basically contains a set of instructions for the proteins in the cell to carry out translation to produce proteins.


But how does the molecule work? Well it affects the ability for the cell to transcribe, repair or replicate the corresponding section of the gene. Like antigens bind to antibody cells or like haemoglobin binds to oxygen molecules, the scientists have engineered this molecule to bond to DNA. The time frame of sixteen days is considered significant, in that it interrupts the reproduction of that particular segment of DNA for up to sixteen days.
Transcription is the process in which the information in DNA is copied onto RNA, a template for future DNA production (Reece et al. 2011). If the DNA influencing the condition of the patient was silenced using the recently discovered molecule, then it would not be transcribed onto the RNA, and therefore the cell would not carry out the particular instruction.

Iverson explained that the binding and interrupting of the DNA information was significant in that it was attacking the root of the problem, such as HIV AIDS, at the source rather than just treating the symptoms (DiCiutiis 2012).

Although this molecule has great potential, there are still road blocks that need to be overcome, such as the requirement for penetration of the cell and the ability for the molecule to hunt down the specific section of the genome. Even then, the molecule would need to be able to connect to the defective gene and also to stay there for as long as possible to increase the chances of the gene to be silenced.

What’s in the future for this technology? Iverson says that they hope to extend the time frame that the molecule will be effective for, increasing on the already staggering sixteen days. (DiCiutiis 2012)


References

Holman, GG, Zewail-Foote, M, Rhoden Smith, A, Johnson KA, & Iverson, BL 2011, ‘A sequence-specific threading tetra-intercalator with an extremely slow dissociation rate constant’, Nature Chemistry, vol. 3, no. 11, pp. 875-881, viewed 14 March 2012, <http://www.nature.com.ezproxy.library.uq.edu.au/nchem/journal/v3/n11/full/nchem.1151.html#/supplementary-information>

The University of Texas 2012, New Molecule Has Potential to Help Treat Genetic Diseases and HIV, viewed March 11 2012, http://www.utexas.edu/news/2012/02/10/dna_entangling_iverson_lab/

DiCiutiis, HJ 2012, UT research successful in DNA binding, possible uses include HIV treatment, The Daily Texan, viewed March 18 2012, http://www.dailytexanonline.com/news/2012/02/27/ut-research-successful-dna-binding-possible-uses-include-hiv-treatment

Wilkins, A 2012, DNA-tangling molecule could revolutionize treatments for cancer and HIV, iO9, viewed March 17 2012, http://io9.com/5885072/dna+tangling-molecule-could-revolutionize-treatments-for-cancer-and-hiv

Reece, JB, Meyers, N, Urry, LA, Cain, ML, Wasserman, SA, Minorsky, PV, Jackson, RB, Cooke, BN 2011, Campbell Biology, 9th edn, Australian Version, Pearson Education, China, pp. 334-397.

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