NIH scientists identify novel approach to view inner workings of viruses

January 12, 2012. — Since the discovery of the microscope, scientists have tried to visualize smaller and smaller structures to provide insights into the inner workings of human cells, bacteria and viruses. Now, researchers at the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), part of the National Institutes of Health, have developed a new way to see structures within viruses that were not clearly seen before. Their findings are reported in the Jan. 13 issue of Science.

Cryo-electron microscopy (cryo-EM) is a technique that allows scientists to image very small particles, like structures on the surface of viruses. This method has been useful in helping researchers understand how vaccines work. But, despite the success of cryo-EM, scientists have been unable to clearly visualize structures inside of viruses, because radiation is used to image them.

In the background, cryo-electron micrographs of purified viruses with their inner structure bubbling from radiation damage. Overlaid, (left) 3D computer reconstruction of a virus’s outer shell and tail in gray, with the inner structure in magenta; (right) blow-up of the inner viral structure in magenta.

“With lower doses of radiation, it is not possible to see inside the organism,” said lead author Dr. Alasdair Steven of the NIAMS Laboratory of Structural Biology Research. “However, higher doses of radiation damage the virus, destroying the very structures that we would like to view.”

Working in collaboration with the group of Dr. Lindsay Black at the University of Maryland Medical School, Baltimore, Steven and his team were able to turn the problem of radiation damage into an asset. Viruses, one of the simplest life forms, are made up of nucleic acids (DNA or RNA) and the proteins encoded by the nucleic acid instruction manual. The researchers realized that proteins inside the virus are more sensitive to damage than DNA.

For more information on the NIAMS Laboratory of Structural Biology Research, visit
www.niams.nih.gov/Research/Ongoing_Research/Branch_Lab/Structural_Biology/default.asp .

The mission of the NIAMS, a part of the U.S. Department of Health and Human Services’ National Institutes of Health, is to support research into the causes, treatment and prevention of arthritis and musculoskeletal and skin diseases; the training of basic and clinical scientists to carry out this research; and the dissemination of information on research progress in these diseases. For more information about the NIAMS, call the information clearinghouse at (301) 495-4484 or (877) 22-NIAMS (free call) or visit the NIAMS website at www.niams.nih.gov .

About the National Institutes of Health (NIH): NIH, the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov .