Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


African parasite makes component of fat differently from all other organisms

Johns Hopkins researchers shed light on the culprit behind 'sleeping sickness'

Studying the parasite that causes African sleeping sickness, scientists at Johns Hopkins have discovered a previously unknown way of making fatty acids, a component of fat and the outer layer of all cells.

The find unveils more about the biology of this hard-to-kill parasite and could lead to a target for designing new drugs to fight the illness that infects a half-million people and kills 50,000 a year worldwide.

Results of the study, in the Aug. 25 issue of Cell, "show that this is a completely new biochemical pathway for making fatty acids," says Soo Hee Lee, Ph.D., a postdoctoral fellow in the Department of Biological Chemistry at the Institute for Basic Biomedical Sciences at Hopkins. "It may be that the enzymes in the pathway could be good targets for designing drugs to treat sleeping sickness."

The single-celled trypanosome that causes African sleeping sickness, transmitted between humans and animals by bloodsucking tsetse flies, goes through several different stages in its life cycle. One such form is harbored by the insect and the other multiplies in a host's bloodstream.

There, the parasite avoids detection by the human immune system by replacing each of the 10 million proteins on its outer layer - known as the cell membrane - with different proteins that are not recognized by immune cells. These proteins are attached to the cell membrane by an anchor composed in part of a fatty acid only 14 units long - dubbed myristate -- whereas typically, in other organisms, these types of anchors contain longer fatty acids, generally 16 or 18 units long.

"For many years we thought the parasite had to get the myristate from its human host because we never could see any evidence that it could make the fatty acid itself," says Paul Englund, Ph.D., a professor of biological chemistry in the Institute of Basic Biomedical Sciences at Hopkins. "Several years ago we found that it does actually make myristate as well as other fatty acids, and now we found that it uses a biochemical pathway we never knew to look for."

They learned about this new fatty acid-making pathway by hunting the trypanosome genome for stretches of DNA known to be involved in fatty acid synthesis in other organisms, like animals and plants.

The researchers reasoned that knocking out the fatty acid-making genes would prevent the parasite from making myristate and other fatty acids.

But when one member of the research team, Jennifer Stephens, knocked out a single gene in the trypanosome known to make fatty acids in other organisms, there was no change in the parasite's ability to make myristate. Surprised, the researchers then examined the trypanosome genome more carefully and discovered enzymes that in other organisms are known to increase the size of a fatty acid molecule - dubbed elongases, for making fatty acids longer - but never have been shown to actually make a new fatty acid molecule.

Lee knocked out these elongases to see if the parasite might have difficulty making fatty acids. To the researchers' surprise, the parasites lacking elongases were unable to make the 14-unit myristate or other fatty acids.

"A novel feature of the elongase pathway is that it contains four different enzymes that take turns in elongating fatty acids," says Lee. "This modular pathway allows the parasite to control the size of the fatty acids it makes."

"It turns out that trypanosomes use an entirely unique mechanism of making fatty acids. No other organism ever studied uses elongases to make them," says Englund, suggesting that attacking biochemical pathways that make fatty acids could be a way to treat sleeping sickness. According to the researchers, the research community is extremely interested in developing drugs that target bacterial enzymes involved in fatty acid synthesis. An example of one is called isoniazid, which currently is used to treat tuberculosis.

"Trypanosomes cause significant health problems in remote areas of Africa with poor health care," says Englund. "There is tremendous need for new drugs to cure these diseases."

Audrey Huang | EurekAlert!
Further information:

Further reports about: African elongase fatty acids myristate organism parasite trypanosome

More articles from Life Sciences:

nachricht North and South Cooperation to Combat Tuberculosis
22.03.2018 | Universität Zürich

nachricht Researchers Discover New Anti-Cancer Protein
22.03.2018 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Modular safety concept increases flexibility in plant conversion

22.03.2018 | Trade Fair News

New interactive map shows climate change everywhere in world

22.03.2018 | Earth Sciences

New technologies and computing power to help strengthen population data

22.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>