Zika, Up Close and Personal
A high-resolution image of Zika offers unprecedented detail of the surface of the flavivirus. Could the information lead us to a vaccine or therapeutics?
One of the biggest mysteries surrounding Zika, a flavivirus spread by the same mosquitoes that transmit yellow fever and dengue virus, is why it manifests birth defects. A high-resolution image published this week in the journal Structure, offers a way for scientists to answer this question. As reported this week in The New York Times, a project led by scientists from Purdue University recently captured the clearest and most detailed image yet of the virus that sparked outbreaks in nearly 50 countries and caused devastating brain damage in thousands of babies whose mothers were infected while they were pregnant. The scientists used cryo-electron microscopy or cryo-EM, a technique that allows you to freeze biomolecules mid-movement and visualize processes not previously seen.
In this case, cryo-EM provided the highest resolution image ever captured of a virus with an envelope or protective outer shell.The glycoprotein interactions and surface properties of the Zika virus were compared with other mosquito-borne flavivirus structures, such as the those that cause yellow fever or dengue. The scientists found that the "largest structural differences and sequence variations occurred at the glycosylation loop associated with receptor binding and that probable drug binding pockets were identified on the viral surface. The microscopic distinctions could explain why dengue develops into a hemorrhagic fever while Zika triggers birth defects, Michael G. Rossmann, a microbiologist at Purdue University and one of the study’s authors, told the Times.
Being able to observe the Zika virus in unprecedented detail means scientists have a better shot at designing a protective vaccine candidate or finding effective therapeutics to treat Zika. But Duane Gubler, an emeritus professor of infectious disease at Duke-NUS Medical School in Singapore, told the Times that while the discover is critical to finding solutions to Zika, it will be while before we have effective therapeutics.
If you would like to hear more abut Dr. Gubler's insights on flaviviruses, check out Eureka's recent Q&A.