Using cryoelectron microscopy and advanced imaging techniques, the Purdue team has determined the orientation of the major surface proteins in a West Nile viral particle. Because these proteins are instrumental in allowing the virus to bind to and invade a host cell, the research could be a step forward in combating the deadly mosquito-borne disease.

"We can now clearly understand how these proteins interact with one another," said Richard J. Kuhn, a professor of biological sciences in Purdue's School of Science. "We can't cure West Nile yet, but we can now start thinking about how to interfere with these interactions, which could be a key to stopping the infection's progress."

The team's work appears in Friday's (10/10) edition of Science.

Viruses are among the smallest of biological entities, containing only essential amounts of genetic material that allow a virus to take over a victim cell's functions. As West Nile develops inside a host cell, several layers of protein molecules assemble themselves around the genetic material, forming a protective shell. The outer layer of proteins is often arranged in an intricate pattern of interlocked molecules that can give the particle's surface the appearance of a lattice or, in the case of West Nile, the fabric of a herringbone jacket. When the mature West Nile virus particle emerges, it is these surface proteins that interact with another cell's surface so the next invasion cycle can begin.

"The West Nile virus is formed from three protein types," Kuhn said. "After the virus assembles in its host cell, these protein molecules fit together like a jigsaw puzzle and form a well-ordered symmetrical particle. From the structure, we now know, essentially, how the major sets of protein molecules interl
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Contact: Chad Boutin
cboutin@purdue.edu
765-494-2081
Purdue University
9-Oct-2003