Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Catalyst sandwich

01.10.2010
Synthetic PCR mimic could lead to highly sensitive medical, environmental diagnostics

Northwestern University researchers have taken another step towards realizing a new class of polymerase chain reaction (PCR) enzyme mimics, opening the door for the development of highly sensitive chemical detection systems that go beyond nucleic acid targets.

The blueprint for building synthetic structures to detect and signal the presence of targets such as small molecule medical analytes (signalers of disease or bodily malfunction, such as neurotransmitters) and environmental hazards, such as TNT, to name just a few, is inspired by biology and its allosteric enzymes. The method also could be useful in catalysis and the production of polymers, including plastics.

The work, which promises higher sensitivity than that of current detection tools, will be published Oct. 1 by the journal Science.

"PCR -- the backbone of the biodiagnostics industry -- is an enzyme that binds to a nucleic acid and changes shape, turning on a catalyst that makes copies of the nucleic acid for detection purposes," said Chad A. Mirkin, George B. Rathmann Professor of Chemistry in the Weinberg College of Arts and Sciences.

"What if you could do that for thousands of small molecules of interest?" he said. "We'd like to be able to detect tiny amounts of targets important to medicine and the environment, opening avenues to new types of diagnostic tools, just as PCR did for the modern fields of medical diagnostics and forensics. Our new catalysts could make that possible."

Mirkin led a team of chemists who built a synthetic structure that, much like the layers of an Oreo cookie, sandwiches the catalyst between two chemically inert layers. This triple-layer architecture allows the use of any catalyst as it will be kept inactive, or in an "off" state, until triggered by a specific small molecule.

The enzyme mimic behaves like allosteric enzymes found in nature, catalysts that change shape to carry out their functions. (Hemoglobin is an example of an allosteric enzyme.) When the mimic reacts with a specific small molecule, the triple-layer structure changes shape and opens, exposing the catalyst. The resulting catalytic reaction signals the presence of the small molecule target, much like PCR amplifies a single piece of DNA.

"One of our challenges as synthetic chemists has been learning to synthesize structures inspired by biology but that have nothing to do with biology other than the fact we'd like such complex functions realized in man-made systems," said Mirkin, also director of Northwestern's International Institute for Nanotechnology.

In the work reported in Science, the researchers use an aluminum salen complex as the catalyst in the three-layer structure. The addition of chloride (the reduced form of chlorine) triggers the catalyst and starts the polymerization process. (Chloride ion binds at an allosteric binding site, distant from the active or catalytic site.) The addition of an agent that removes the chloride stops the process, but the chloride can be added back to start it again.

The title of the paper is "Allosteric Supramolecular Triple-Layer Catalysts." In addition to Mirkin, other authors of the paper are Hyo Jae Yoon, Junpei Kuwabara and Jun-Hyun Kim, all from Northwestern.

Megan Fellman | EurekAlert!
Further information:
http://www.northwestern.edu

More articles from Life Sciences:

nachricht Link Discovered between Immune System, Brain Structure and Memory
26.04.2017 | Universität Basel

nachricht Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli

26.04.2017 | Agricultural and Forestry Science

SwRI-led team discovers lull in Mars' giant impact history

26.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>