Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stacking at the flick of a switch

14.12.2009
A switch that controls formation of stacks from nucleic acid strands has potential applications in gene expression and molecular machines

Small, structured nucleic acid strands designed to interact with specific target molecules, known as aptamers, are particularly interesting to scientists as therapeutics against viruses and blood clotting disorders. Aptamers that bind strongly to target enzymes or proteins can prevent their activity, thereby regulating the biological process they control.

Aptamers frequently contain stacks of hydrogen-bonded guanine-rich sequences, called quadruplexes, which enable effective binding to targets. When these structures are disrupted or destroyed—perhaps through poor replication—the aptamer can no longer bind. Interestingly, the reversible formation and disruption of these quadruplexes have the potential to be controlled using external stimuli, leading to a switching on and off of the aptamer's binding. Using this idea, Shinzi Ogasawara and Mizuo Maeda at the RIKEN Advanced Science Institute in Wako, have developed a light-controlled switch to control quadruplex formation in an aptamer that binds specifically to thrombin1, the protein in blood that control blood coagulation.

The researchers developed a range of modified aptamers that contained various numbers of potential quadruplex structural units. Using light they were able to switch and select between a stable quadruplex and a non-structured state. Using light to control a switch allows accurate and easy control of the location, dosage, and timing. They then screened their variant aptamers to determine the best number and positions of the structural units to give effective regulation.

More specifically, Ogasawara and Maeda were able to control the switching behavior using light of specific wavelengths. In solution, they found that when the quadruplex is present, the aptamer binds strongly to thrombin. When the sample was irradiated at 410 nanometers, the double bonds within the complex changed from a so-called trans configuration to a cis configuration that disrupted the quadruplex and suppressed binding of the aptamer. Irradiation at 310 nanometers, however, changed the bonds back into the trans form, allowing the quadruplex to re-form and bind once again.

Ogasawara and Maeda realized that the release-and-bind steps could be repeated over two cycles. First, they irradiated a reaction sample at 410 nanometers for 5 minutes and then at 310 nanometers for 2 minutes. After repeating the irradiation cycle, they found that the switch was completely reversible, and they detected no side reactions, thus demonstrating its potential in living cells.

Ogasawara and Maeda now plan to apply this technique to investigate other important biological events involving quadruplexes, such as gene expression and the construction of molecular machines.

The corresponding author for this highlight is based at the Bioengineering Laboratory, RIKEN Advanced Science Institute

Saeko Okada | Research asia research news
Further information:
http://www.rikenresearch.riken.jp/eng/research/6086
http://www.researchsea.com

More articles from Life Sciences:

nachricht Closing the carbon loop
08.12.2016 | University of Pittsburgh

nachricht Newly discovered bacteria-binding protein in the intestine
08.12.2016 | University of Gothenburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>