- News Home
17 April 2014 12:48 pm ,
Vol. 344 ,
Officials last week revealed that the U.S. contribution to ITER could cost $3.9 billion by 2034—roughly four times the...
An experimental hepatitis B drug that looked safe in animal trials tragically killed five of 15 patients in 1993. Now,...
Using the two high-quality genomes that exist for Neandertals and Denisovans, researchers find clues to gene activity...
A new report from the Intergovernmental Panel on Climate Change (IPCC) concludes that humanity has done little to slow...
Astronomers have discovered an Earth-sized planet in the habitable zone of a red dwarf—a star cooler than the sun—500...
Three years ago, Jennifer Francis of Rutgers University proposed that a warming Arctic was altering the behavior of the...
- 17 April 2014 12:48 pm , Vol. 344 , #6181
- About Us
Disease Fighter Found in Fungi
12 October 2005 (All day)
Twenty years ago no one knew that defensins, a special class of molecules that combat both viruses and bacteria, even existed. They've since been found in nearly every complex organism, yet scientists haven't been able to harness them as disease-fighters. Now, defensins have been discovered in fungi for the first time, a finding that may be key to finally mass-producing these compounds and offering them to patients.
Defensins are short chains of amino acids that poke holes in bacterial membranes, killing the pathogen. They also bind to and disable certain viruses. Nearly every multicellular organism appears to make defensins, with humans alone producing almost 30 different types. But scientists have not been able to mass-produce pure enough concentrations of defensins for drug development and testing, largely because research relies upon fungal-based manufacturing systems developed for penicillin and other antibiotics.
That may change thanks to the discovery of a defensin called plectasin in Pseudoplectania nigrella--a black fungus that grows in European pine forests. The researchers, led by Hans-Henrik Kristensen and Per H. Mygind, both microbiologists at Novozymes, were able to generate large quantities of plectasin by plugging the gene into a fungal protein expression system. To test plectasin's therapeutic benefits, the team gave the compound to mice infected with Streptococcus pneumoniae, the bacterium that causes pneumonia, meningitis, and strep throat. Plectasin was as effective at killing the bugs as penicillin and vancomycin, two commonly prescribed antibiotics. All plectasin-treated mice infected with common strains were cured, and 80% of the mice infected with aggressive strains showed no sign of illness after three days, the researchers report 13 October in Nature.
"There have been several attempts to develop defensins as useful therapeutics, but these attempts have fallen just short of their goal," says Charles Bevins, an immunologist at the University of California, Davis. "This study shows that sufficient plectasin can be generated to allow for a cost-effective means of drug production."