Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bionic bacteria may help fight disease and global warming

22.09.2011
Salk Institute researchers have built artificially enhanced bacteria capable of producing new kinds of synthetic chemicals

A strain of genetically enhanced bacteria developed by researchers at the Salk Institute for Biological Studies may pave the way for new synthetic drugs and new ways of manufacturing medicines and biofuels, according to a paper published September 18 in Nature Chemical Biology.

For the first time, the scientists were able to create bacteria capable of effectively incorporating "unnatural" amino acids - artificial additions to the 20 naturally occurring amino acids used as biological building blocks - into proteins at multiple sites. This ability may provide a powerful new tool for the study of biological processes and for engineering bacteria that produce new types of synthetic chemicals.

"This provides us with a lot more room to think about what we can do with protein synthesis," said Lei Wang, assistant professor in Salk's Chemical Biology and Proteomics Laboratory and holder of the Frederick B. Rentschler Developmental Chair. "It opens up new possibilities, from creating drugs that last longer in the blood stream to manufacturing chemicals in a more environmentally friendly manner."

In 2001, Wang and his colleagues were the first to create bacteria that incorporated unnatural amino acids (Uaas) into proteins, and, in 2007, they first used the technique in mammalian cells. They did this by creating an "expanded genetic code," overriding the genetic code of the cells and instructing them to use the artificial amino acids in the construction of proteins.

The addition of Uaas changes the chemical properties of proteins, promising new ways to use proteins in research, drug development and chemical manufacturing.

For instance, Wang and his colleagues have inserted Uaas that will glow under a microscope when exposed to certain colors of light. Because proteins serve as the basis for a wide range of cellular functions, the ability to visualize this machinery operating in live cells and in real time helps scientists decipher a wide range of biological mechanisms, including those involved in the development of disease and aging.

Genetically modified bacteria are already used for producing medicines, such as synthetic insulin, which has largely replaced the use of animal pancreases in the manufacture of drugs used by diabetics to regulate their blood sugar levels.

To date, such recombinant DNA technology has used only natural amino acids, which limits the possible functions of the resulting protein products. The ability to insert Uaas could dramatically expand the possible uses of such technology, but one major barrier has limited the use of Uaas: only a single Uaa at a time could be incorporated into a protein.

To insert the instructions for including a Uaa in a bacterium's genetic code, Wang and his colleagues exploited stop codons, special sequences of code in a protein's genetic blueprint. During protein production, stop codons tell the cellular machinery to stop adding amino acids to the sequence that forms backbone of the protein's structure.

In 2001, Wang and his colleagues modified the genetic sequence of the bacteria Escherichia coli to selectively include a stop codon and introduced engineered molecules inside the bacteria, which surgically insert a Uaa at the stop codon. This trained the bacteria to produce proteins with the Uaa incorporated in their backbone.

The problem was that another biological actor, a protein known as release factor 1 (RF1), would stop the production of a Uaa-containing protein too early. Although scientists could insert stop codons for Uaas at multiple places along genetic sequence, the release factor would cut the protein off at the first stop codon, preventing production of long proteins containing multiple Uaas.

"To really make use of this technology, you want to be able to engineer proteins that contain unnatural amino acids at multiple sites, and to produce them in high efficiency," Wang said. "It was really promising, but, until now, really impractical."

In their new paper, the Salk researchers and their collaborators at the University of California, San Diego described how they got around this limitation. Since RF1 hindered production of long Uaa-containing proteins, the scientists removed the gene that produces RF1. Then, because E. Coli dies when the RF1 gene is deleted, they altered production of an alternative actor, release factor 2 (RF2), so that it could rescue the engineered bacterium.

The result was a strain of bacteria capable of efficiently producing proteins containing Uaas at multiple places. These synthetic molecules hold promise for the development of drugs with biological functions far beyond what is possible with proteins that include only naturally occurring amino acids. They may also serve as the basis for manufacturing everything from industrial solvents to biofuels, possibly helping to address the economic and environmental concerns associated with petroleum-based manufacturing and transportation.

"This is the first time we've been able to produce a viable strain of bacteria capable of this," Wang said. "We still have a ways to go, but this makes the possibility of using unnatural amino acids in biological engineering far closer to being reality."

he research was funded by the Beckman Young Investigator Program, the California Institute for Regenerative Medicine, the March of Dimes Foundation, the Mary K. Chapman Foundation, the National Institutes of Health, the National Science Foundation, the Pioneer Fellowship, the Ray Thomas Edwards Foundation and the Searle Scholar Program.

Andy Hoang | EurekAlert!
Further information:
http://www.salk.edu

More articles from Life Sciences:

nachricht Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory

nachricht Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

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...

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

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>