Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Expression of Infrared Fluorescence Engineered in Mammals

11.05.2009
Researchers at the University of California, San Diego – led by 2008 Nobel-Prize winner Roger Tsien, PhD – have shown that bacterial proteins called phytochromes can be engineered into infrared-fluorescent proteins (IFPs). Because the wavelength of IFPs is able to penetrate tissue, these proteins are suitable for whole-body imaging in small animals.

Researchers at the University of California, San Diego – led by 2008 Nobel-Prize winner Roger Tsien, PhD – have shown that bacterial proteins called phytochromes can be engineered into infrared-fluorescent proteins (IFPs).

Because the wavelength of IFPs is able to penetrate tissue, these proteins are suitable for whole-body imaging in small animals. Their findings will be published in the May 8 edition of the journal Science.

“The development of IFPs may be important for future studies in animals – to find out how cancers develop, how infections grow or diminish in mice, or perhaps how neurons are firing in flies,” said Tsien, professor of pharmacology, chemistry and biochemistry at UC San Diego and a Howard Hughes Medical Institute investigator. Tsien was one of three scientists awarded the 2008 Nobel Prize in Chemistry for discovery of the Green Fluorescent Protein (GFP) and a series of important developments which have led to its use as a tagging tool in bioscience.

The limitation of using GFP in living mammals is that its wave lengths are not long enough to allow light to penetrate far enough to allow inner cells to glow with fluorescent light.

First author Xiaokun Shu, PhD, of the UC San Diego School of Medicine’s Department of Pharmacology and the Howard Hughes Medical Institute, coerced the phytochrome from the bacteria Deinococcus radiodurans to fluoresce – the first protein to glow in infrared and work in mouse models. A phytochrome is a photoreceptor – a pigment that plants and bacteria use to detect light – which is sensitive to light in the red and far-red region of the visible spectrum.

“IFPs express well in mammalian cells and spontaneously incorporate biliverdin, a green pigment that is present in humans and other mammals,” said Tsien. Biliverdin is the substance responsible for the yellowish-green color of a bruise as it fades, for example. Biliverdin normally has negligible fluorescence. However, Shu was able to coax the biliverdin-containing protein to fluoresce by cutting off the parts of the phytochrome that divert the energy of the light.

“We hoped that by doing so, the light’s energy wouldn’t go anywhere else but would instead go out and become fluorescent,” Shu said, adding that the protein is “moderately fluorescent, but we still have a long way to go.”

Tsien stated that, while this work is promising for future studies in animal models, he doesn’t think it will be applied directly to imaging in humans for several reasons.

“First, all fluorescent proteins derived from corals, jellyfish, and now bacteria are powerful in basic research because they are encoded by a gene,” said Tsien. “Introducing such genes into people would pose big scientific and ethical problems.”

He explained that, secondly, humans are still too thick and opaque for the infrared fluorescence to get deep inside our bodies, although scientists can now see faintly through a mouse with infrared, because mice are so much smaller.

The Tsien lab is working on a different project to develop a technique without these limitations, one that can be used for imaging in humans. His hope is that, one day, people will be able to go in for their annual check ups and know if they have cancer because tumors will light up by magnetic resonance imaging of diagnostic molecules.

But for now, Tsien, Shu and their colleagues at UC San Diego hope that the prototype they have developed can be used to make other, improved fluorescent bacterial proteins from among the huge numbers harnessed from other organisms – IFPs that can be used in important animal studies.

This technology (SD2008-303) and related technologies are available for licensing and commercial development through the UCSD Technology Transfer Office (http://invent.ucsd.edu).

Debra Kain | Newswise Science News
Further information:
http://www.ucsd.edu

More articles from Life Sciences:

nachricht Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz

nachricht Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB

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

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | 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

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>