Tropical malaria is responsible for more than 1.2 million deaths annually. Severe forms of the disease are mainly caused by the parasite Plasmodium falciparum, transmitted to humans by female Anopheles mosquitoes. Malaria eradication has not been possible due to the lack of vaccines and the parasite's ability to develop resistance to most drugs.
This is an illustration of Anopheles darlingi.
Credit: UC San Diego School of Medicine
The researchers conducted high-throughput screening of nearly 350,000 compounds in the National Institutes of Health's Molecular Libraries Small Molecule Repository (MLSMR) to identify compounds that inhibit an enzyme which plays an important role in parasite development: Plasmodium falciparum glucose-6-phosphate dehydrogenase (PfG6PD) is essential for proliferating and propagating P. falciparum.
"The enzyme G6PD catalyzes an initial step in a process that protects the malaria parasite from oxidative stress in red blood cells, creating an environment in which the parasite survives," said senior author Lars Bode, PhD, assistant professor in the UCSD Department of Pediatrics, Division of Neonatology and the Division of Gastroenterology, Hepatology and Nutrition. People with a natural deficiency in this enzyme are protected from malaria and its deadly symptoms, an observation that triggered the reported research.
The parasitic form of the enzyme (PfG6PD) is what contributes the majority of G6PD activity in infected red blood cells. Because the parasite lives in the blood of a malaria-infected person, the scientists aimed at identifying compounds that inhibit the parasitic form but not the human form of the enzyme. "We didn't want to interfere with the human form of the enzyme and risk potential side effects," Bode explained.
Scientific testing had previously been limited by a lack of recombinant PfG6PD. Team members in the lab of Katja Becker, PhD, at the Interdisciplinary Research Center at Justus-Liebig-University in Giessen, Germany produced the first complete and functional recombinant PfG6PD, and researchers led by Anthony Pinkerton, PhD, at Sanford-Burnham Medical Research Institute used it to identify the lead compound resulting from their efforts, ML276.
ML276 represents the first reported selective PfG6PD inhibitor, which stops the growth of malaria parasites in cultured red blood cells – even those parasites that developed resistance to currently available drugs. "ML276 is a very promising basis for future drug design of new anti-malarial therapeutics," said Bode.
Contributors to the study include Janina Preuss, UC San Diego, Justus-Liebig-University and Sanford-Burnham Medical Research Institute; Esther Jortzik, Stefan Rahlfs and Katja Becker, Justus-Liebig-University; Patrick Maloney, Satyamaheshwar Peddibhotla, Paul Hershberger, Eliot Sugarman, Becky Hood, Eigo Suyama, Kevin Nguyen, Stefan Vasile, Arianna Mangravita-Novo, Michael Vicchiarelli, Danielle McAnally, Layton H. Smith. Gregory P. Roth, Michael P. Hedrick, Palak Gosalia, Monika Milewski, Yujie Linda Li, Eduard Sergienko, Jena Diwan, Thomas D.Y. Chung, and Anthony B. Pinkerton, Sanford-Burnham.
The study was supported by the National Institutes of Health (1R21AI082434), the Deutsche Forschungsgemeinschaft, and an NIH Molecular Libraries grant (U54 HG005033) to the Conrad Prebys Center for Chemical Genomics at Sanford Burnham Medical Research Institute, one of the comprehensive centers of the NIH Molecular Libraries Probe Production Centers Network (MLPCN).
Debra Kain | EurekAlert!
Study shines light on brain cells that coordinate movement
26.06.2017 | University of Washington Health Sciences/UW Medicine
New insight into a central biological dogma on ion transport
26.06.2017 | Aarhus University
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
26.06.2017 | Life Sciences
26.06.2017 | Physics and Astronomy
26.06.2017 | Information Technology