Viruses are pesky germs that have evolved a battery of strategies to outwit the body's defenses. Now scientists have discovered that one virus, HK97, does battle in a coat of armor similar to the chain-mail suits worn by medieval knights. The research, which was reported in the Sept. 22 issue of Science, has major implications for nanomedicine, a rapidly growing research area that uses tiny machines to repair the body on the molecular level.
An international team of scientists used special micro-imaging techniques to analyze HK97's outer shell. "The proteins in the coat loop through each other--much like the Olympic rings," says lead author William R. Wikoff of the Scripps Research Institute in La Jolla, Calif. Wikoff calls these interlocking protein rings "catenanes" and believes they could be the secret to the virus' toughness. Just as chain mail is designed to deflect arrows, these catenanes are built to repel insults from the body's immune system and the environment.
Wikoff believes that researchers will one day use HK97 to carry drugs or chemicals to specific locations in the body. Empty it of its DNA, and the virus is a "molecular balloon--big and thin-walled--that can be filled up with anything," he says.