Cure for 'deadly' Ebola virus comes closer to reality

Scientists have discovered the molecular mechanism by which the 'deadly' Ebola virus assembles, paving way for potential new drug targets.
The study at The Scripps Research Institute (TSRI) showed that the same molecule that assembles and releases new viruses also rearranges itself into different shapes, with each shape controlling a different step of the virus's life cycle.
"Like a 'Transformer', this protein of the Ebola virus adopts different shapes for different functions," said Erica Ollmann Saphire, professor in the Department of Immunology and Microbial Science at TSRI.
"These findings open doors to developing new drugs against Ebola," added Zachary Bornholdt, senior staff scientist and first author of the study.

"Drugs to block viral replication could target any of the structures themselves or the intermediate steps in the structural transformation process," said Bornholdt.
Ebola hemorrhagic fever is one of the most virulent diseases known to humankind. Very few pathogens prove more dangerous than Ebola virus once a person is infected.

There is no cure, and the case-fatality rate can be up to 90 per cent, depending on which strain is involved, researchers said.
Ebola virus and its cousin Marburg virus are spread when people come into contact with the bodily fluids of a person or animal who is already infected. Infection causes rapidly progressing high fever, hemorrhage and shock. No drugs or vaccines are yet available for human use.

Once rare, the viruses are now reemerging with increasing frequency, and have caused at least four outbreaks among humans in the last two years.
To conduct the study, Saphire and her group collaborated with Yoshihiro Kawaoka, who holds joint appointments at the University of Wisconsin and University of Tokyo.
The results, five years in the making, revealed the Ebola VP40 protein exists as a dimer, not as a monomer as previously thought, and it rearranges its structure to assemble filaments to build the virus shell or "matrix" to release countless new viruses from infected cells.
The study showed the protein also rearranges itself into rings in order to bind RNA and control the internal components of the virus copied inside infected cells.

The study was published in the journal Cell.