When Solov'yov showed that superoxide would work well as a reaction partner, Schulten was at first dismissive.
"But then I realized that the toxicity of superoxide was actually crucial to its role," he said. The body has many mechanisms for reducing concentrations of superoxide to prevent its damaging effects, Schulten said. But this gives an advantage, since the molecule must be present at low concentrations but not too low "to make the biochemical compass work effectively," he said.
Although known primarily as an agent of aging and cellular damage, superoxide recently has been recognized for its role in cellular signaling.
However, its toxicity may also explain why humans, who also have cryptochrome in their eyes, do not have the same ability to see Earth's electromagnetic field, Schulten said.
"Our bodies try to play it safe," he said. "It might be that human evolution chose longevity over orientational ability."
|Contact: Diana Yates|
University of Illinois at Urbana-Champaign