July 17 (UPI) -- Scientists are utilizing the International Space Station's microgravity in the search for improved antidotes for chemical agents like sarin and VX.
"With increasing worldwide concern about the use of chemical weapons, there is significant interest in developing better counteragents," David A. Jett, director of the CounterACT program at the National Institute of Neurological Disorders and Stroke, said in a news release.
The toxic nerve agents sarin and VX are part of a group of chemicals called organophosphates, which disrupt the activity of acetylcholinesterase, an enzyme that helps muscles relax after they're stimulated by the nervous system. When AChE activity is blocked, muscles can't relax, resulting in paralysis and death.
Scientists at NINDS have recruited astronauts aboard the International Space Station to help them grow crystals of the AChE enzyme. On Earth, gravity disrupts the crystallization process. Under microgravity conditions, crystals of the pure enzyme can grow to much larger sizes.
"By taking advantage of the microgravity conditions of the International Space Station, we hope to grow better, more uniform crystals that we are unable to grow on Earth," said Andrey Kovalevsky, a researcher at the Oak Ridge National Laboratory in Oak Ridge, Tenn.
Once the AChE crystals are fully formed, the enzyme samples will be returned from space to the researchers at NINDS. Once the samples are back in the lab, scientists will use an imaging technique called neutron diffraction to analyze the enzyme's atomic-scale structures.
In order to create effective antidotes to organophosphates, researchers need to better understand the molecular structure of acetylcholinesterase.
"We will be able to get a closer look at how the enzyme interacts with pesticides and nerve agents and learn about how the bond between the two can be chemically reversed," said Zoran Radić, a researcher at the University of California, San Diego. "This method would not work on the smaller enzyme crystals that can be grown here."