(Press-News.org) This news release is available in German.
Scientists of the KIT and the University of Kiev have produced an antibiotic, whose biological activity can be controlled with light. Thanks to the robust diarylethene photoswitch, the antimicrobial effect of the peptide mimetic can be applied in a spatially and temporally specific manner. This might open up new options for the treatment of local infections, as side effects are reduced. The researchers present their photoactivable antibiotic with the new photomodule in a "Very Important Paper" of the journal "Angewandte Chemie".
Photoswitchable molecules modify their structure and properties when exposed to light of an adequate wavelength. Among the photoswitches known are diarylethenes. By reversible photoisomerization, i.e. a reversible light-induced internal relocation of the molecule, the open form is turned into a closed form. Such photoswitch-able molecules are applied in molecular electronics and many other areas. Particularly interesting opportunities result from the insertion of photoswitches into biomolecules to control their activity by light. Interest focuses on so-called peptide mimetics, compounds whose major structural elements emulate a peptide, i.e. a small protein.
For the first time now, a group of researchers headed by Professor Anne S. Ulrich, Director of the Institute for Biological Interfaces 2 (IBG2) and holder of the Chair for Biochemistry at the Institute of Organic Chemistry (IOC) of KIT, has produced a photoswitchable peptide mimetic based on a diarylethene scaffold that can be photoisomerized reversibly. The scientists modified this building block into an amino acid analog and incorporated it directly into the backbone of the annular peptide antibiotic Gramicidin S. Biological activity of the resulting peptide mimetic can be controlled spatially and temporally with the help of UV and visible light. To demonstrate this, the scientists treated a bacterial film with the inactivated antibiotic and exposed it to light via a mask. As a result, the photoswitchable diarylethene was converted from a closed into an open form. Due to the structural modification induced, the entire substance molecule had a much higher antimicrobial effect. "In the future, such photoactivable antibiotics might be used as smart therapeutic agents against local bacterial infections," Professor Anne S. Ulrich explains. "Usual side effects can also be minimized by switching." Based on this strategy, new peptide-based agents against cancer might be feasible, as the newly developed photoactivable building block can also be applied in other peptide sequences.
The editors of the journal "Angewandte Chemie", in which the researchers of KIT and the University of Kiev present their photo-activable antibiotic and their photoswitch, have rated this publication a "VIP – Very Important Paper".
INFORMATION:
Oleg Babii, Sergii Afonin, Marina Berditsch, Sabine Reißer, Pavel K. Mykhailiuk, Vladimir S. Kubyshkin, Thomas Steinbrecher, Anne S. Ulrich, and Igor V. Komarov: Controlling Biological Activity with Light: Diarylethene-Containing Cyclic Peptidomimetics. Angewandte Chemie (2014). DOI: 10.1002/ange.201310019
Karlsruhe Institute of Technology (KIT) is a public corporation according to the legislation of the state of Baden-Württemberg. It fulfills the mission of a university and the mission of a national research center of the Helmholtz Association. Research activities focus on energy, the natural and built environment as well as on society and technology and cover the whole range extending from fundamental aspects to application. With about 9000 employees, including nearly 6000 staff members in the science and education sector, and 24000 students, KIT is one of the biggest research and education institutions in Europe. Work of KIT is based on the knowledge triangle of research, teaching, and innovation.
This press release is available on the internet at http://www.kit.edu.
The photo of printing quality may be downloaded under http://www.kit.edu or requested by mail to presse@kit.edu or phone +49 721 608-4 7414. The photo may be used in the context given above exclusively.
Switching an antibiotic on and off with light
2014-03-21
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
cfaed presents the new microchip 'Tomahawk 2' at the DATE'14 in Dresden
2014-03-21
The Center for Advancing Electronics Dresden (cfaed) presents its new microchip 'Tomahawk 2' at the DATE'14 Conference in the International Congress Center Dresden from March 24 to 28, 2014. The new Tomahawk is extremely fast, energy-efficient and resilient. It is a heterogeneous multi-processor which can easily integrate very different kinds of devices. The researchers of the Cluster of Excellence for microelectronics of Technische Universität Dresden use the new prototype to prepare the so-called 'tactile internet'. With this, very big data volumes shall be transmitted ...
New study shows we work harder when we are happy
2014-03-21
Happiness makes people more productive at work, according to the latest research from the University of Warwick.
Economists carried out a number of experiments to test the idea that happy employees work harder. In the laboratory, they found happiness made people around 12% more productive.
Professor Andrew Oswald, Dr Eugenio Proto and Dr Daniel Sgroi from the Department of Economics at the University of Warwick led the research.
This is the first causal evidence using randomized trials and piece-rate working. The study, to be published in the Journal of Labor Economics, ...
Surprising new way to kill cancer cells
2014-03-21
Northwestern Medicine scientists have demonstrated that cancer cells – and not normal cells – can be killed by eliminating either the FAS receptor, also known as CD95, or its binding component, CD95 ligand.
"The discovery seems counterintuitive because CD95 has previously been defined as a tumor suppressor," said lead investigator Marcus Peter, professor in medicine-hematology/Oncology at Northwestern University Feinberg School of Medicine. "But when we removed it from cancer cells, rather than proliferate, they died."
The findings were published March 20 in Cell Reports. ...
Stem cell study finds source of earliest blood cells during development
2014-03-21
Irvine, Calif., March 20, 2014 — Hematopoietic stem cells are now routinely used to treat patients with cancers and other disorders of the blood and immune systems, but researchers knew little about the progenitor cells that give rise to them during embryonic development.
In a study published April 8 in Stem Cell Reports, Matthew Inlay of the Sue & Bill Gross Stem Cell Research Center and Stanford University colleagues created novel cell assays that identified the earliest arising HSC precursors based on their ability to generate all major blood cell types (red blood ...
New infrared technique aims to remotely detect dangerous materials
2014-03-21
For most people, infrared technology calls to mind soldiers with night-vision goggles or energy audits that identify where heat escapes from homes during the winter season.
But for two Brigham Young University professors, infrared holds the potential to spot from afar whether a site is being used to make nuclear weapons.
Statistics professor Candace Berrett developed a model that precisely characterizes the material in each pixel of an image taken from a long-wave infrared camera. The U.S. National Nuclear Security Administration funded the project through a grant ...
The gene family linked to brain evolution is implicated in severity of autism symptoms
2014-03-21
The same gene family that may have helped the human brain become larger and more complex than in any other animal also is linked to the severity of autism, according to new research from the University of Colorado Anschutz Medical Campus.
The gene family is made up of over 270 copies of a segment of DNA called DUF1220. DUF1220 codes for a protein domain – a specific functionally important segment within a protein. The more copies of a specific DUF1220 subtype a person with autism has, the more severe the symptoms, according to a paper published in the PLoS Genetics. ...
Stanford professor maps by-catch as unintended consequence of global fisheries
2014-03-21
Seabirds, sea turtles and marine mammals such as dolphins may not appear to have much in common, other than an affinity for open water. The sad truth is that they are all unintended victims – by-catch – of intensive global fishing. In fact, accidental entanglement in fishing gear is the single biggest threat to some species in these groups.
A new analysis co-authored by Stanford biology Professor Larry Crowder provides an unprecedented global map of this by-catch, starkly illustrating the scope of the problem and the need to expand existing conservation efforts in certain ...
Homeless with TBI more likely to visit ER
2014-03-21
TORONTO, March 21, 2014—Homeless and vulnerably housed people who have suffered a traumatic brain injury at some point in their life are more likely to visit an Emergency Department, be arrested or incarcerated, or be victims of physical assault, new research has found.
"Given the high costs of Emergency Department visits and the burden of crime on society, these findings have important public health and criminal justice implications," the researchers from St. Michael's Hospital wrote today in the Journal of Head Trauma Rehabilitation.
Traumatic brain injuries, such as ...
Dust in the wind drove iron fertilization during ice age
2014-03-21
Researchers from Princeton University and the Swiss Federal Institute of Technology in Zurich have confirmed that during the last ice age iron fertilization caused plankton to thrive in a region of the Southern Ocean.
The study published in Science confirms a longstanding hypothesis that wind-borne dust carried iron to the region of the globe north of Antarctica, driving plankton growth and eventually leading to the removal of carbon dioxide from the atmosphere.
Plankton remove the greenhouse gas carbon dioxide (CO2) from the atmosphere during growth and transfer it ...
Obesity and depression linked in teen girls says new Rutgers-Camden study
2014-03-21
Depression and obesity have long been associated, but how they relate over time is less clear. New research from a Rutgers University–Camden professor shows that adolescent females who experience one of the disorders are at a greater risk for the other as they get older.
"Adolescence is a key developmental period for both obesity and depression, so we thought it significant to look at the onset of these disorders at an early age," says Naomi Marmorstein, an associate professor of psychology at Rutgers–Camden.
By assessing a statewide sample of more than 1,500 males ...