Using a novel analytical process, researchers at the Georgia Institute of Technology found that the complex antifungal molecules are not distributed evenly across the seaweed surfaces, but instead appear to be concentrated at specific locations – possibly where an injury increases the risk of fungal infection.
A Georgia Tech scientist will report on the class of compounds, known as bromophycolides, at the annual meeting of the American Association for the Advancement of Science (AAAS) Feb. 21, 2011 in Washington, D.C. The research, supported by the National Institutes of Health, is part of a long-term study of chemical signaling among organisms that are part of coral reef communities.
"The language of chemistry in the natural world has been around for billions of years, and it is crucial for the survival of these species," said Julia Kubanek, an associate professor in Georgia Tech's School of Biology and School of Chemistry and Biochemistry. "We can co-opt these chemical processes for human benefit in the form of new treatments for diseases that affect us."
More than a million people die each year from malaria, which is caused by the parasite Plasmodium falciparum. The parasite has developed resistance to many antimalarial drugs and has begun to show resistance to artemisinin – today's most important antimalarial drug. The stakes are high because half of the world's population is at risk for the disease.
"These molecules are promising leads for the treatment of malaria, and they operate through an interesting mechanism that we are studying," Kubanek explained. "There are only a couple of drugs left that are effective against malaria in all areas of the world, so we are hopeful that these molecules will continue to show promise as we develop them further as pharmaceutical leads."In laboratory studies led by Georgia Tech student Paige Stout from Kubanek's lab – and in collaboration with California scientists – the lead molecule has shown promising activity against malaria, and the next step will be to test it in a mouse model of the disease. As with other potential drug compounds, however, the likelihood that this molecule will have just the right chemistry to be useful in humans is relatively small.
The researchers found the antifungal compounds associated with light-colored patches on the surface of the Callophycus serratus seaweed using a new analytical technique known as desorption electrospray ionization mass spectrometry (DESI-MS). The technique was developed in the laboratory of Facundo Fernandez, an associate professor in Georgia Tech's School of Chemistry and Biochemistry. DESI-MS allowed researchers for the first time to study the unique chemical activity taking place on the surfaces of the seaweeds.
As part of the project, Georgia Tech scientists have been cataloging and analyzing natural compounds from more than 800 species found in the waters surrounding the Fiji Islands. They were interested in Callophycus serratus because it seemed particularly adept at fighting off microbial infections.
Using the DESI-MS technique, researchers Leonard Nyadong and Asiri Galhena analyzed samples of the seaweed and found groups of potent antifungal compounds. In laboratory testing, graduate student Amy Lane found that these bromophycolide compounds effectively inhibited the growth of Lindra thalassiae, a common marine fungus.
"The alga is marshalling its defenses and displaying them in a way that blocks the entry points for microbes that might invade and cause disease," Kubanek said. "Seaweeds don't have immune responses like humans do. But instead, they have some chemical compounds in their tissues to protect them."Though all the seaweed they studied was from a single species, the researchers were surprised to find two distinct groups of antifungal chemicals. From one seaweed subpopulation, dubbed the "bushy" type for its appearance, 23 different antifungal compounds were identified. In a second group of seaweed, the researchers found 10 different antifungal compounds — all different from the ones seen in the first group.
"Our collaborative team of researchers from the Department of Biomedical Engineering and the College of Sciences has worked within the Bioimaging Mass Spectrometry Center at Georgia Tech to better understand the mechanisms of chemical defenses in marine organisms," said Fernandez. "This is an example of cross-cutting interdisciplinary research that characterizes our institute."
Kubanek is hopeful that other useful compounds will emerge from the study of signaling compounds in the coral reef community.
"In the natural world, we have seaweed that is making these molecules and we have fungi that are trying to colonize, infect and perhaps use the seaweed as a substrate for its own growth," Kubanek said. "The seaweed uses these molecules to try to prevent the fungus from doing this, so there is an interaction between the seaweed and the fungus. These molecules function like words in a language, communicating between the seaweed and the fungus."
This presentation, "Warding Off Disease on Coral Reefs: Antifungal Chemical Cues in Tropical Seaweed" will be part of the session "Chemically Speaking: How Organisms Talk to Each Other" on Monday, February 21 at 9:45 a.m. The topic will also be part of a news briefing held at 8 a.m. that day.
John Toon | EurekAlert!
Hunting pathogens at full force
22.03.2017 | Helmholtz-Zentrum für Infektionsforschung
A 155 carat diamond with 92 mm diameter
22.03.2017 | Universität Augsburg
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
22.03.2017 | Materials Sciences
22.03.2017 | Physics and Astronomy
22.03.2017 | Materials Sciences