In ground-based laboratories, like Borgstahl's at the University of Toledo, researchers mix up and try out thousands of recipes at a time - trying to coax proteins to form crystals that will reveal how they are made.
So why use an orbiting laboratory hundreds of miles away in space?
Some proteins form crystals perfectly on the ground. Some form small, irregular crystals that are difficult to study and won't reveal how proteins are made. Some won't form crystals at all.
In the microgravity environment created as the Space Station orbits Earth, crystals float in their solutions - much like the astronauts float through the Station. On Earth, the heavy crystals sediment, or sink, to the bottom of flasks and often stick together. This sometimes results in small, cracked, poorly formed crystals.
Borgstahl and Snell got their first taste of success on the STS-95 Space Shuttle mission in October 1998 when U.S. Sen. John Glenn of Ohio helped grow crystals of insulin in microgravity for the Hauptman-Woodward Medical Research Institute in Buffalo, New York. Snell and Borgstahl analyzed the quality of the insulin crystals. They found the space-grown crystals were 34 times larger than those grown on the ground. (Acta Crystallographic, 2001, D57, 254-259)
"More importantly than being large, the crystals had better internal order," said Snell. "Our thorough analysis showed microgravity passed the test, providing the best environment for growing macromolecules of these proteins."
Better internal order means that scientists can fire X-ray beams at the crystal and learn how it is made at the atomic an/or electronic level. It is like working a puzzle backwards. You have a crystal - the completed puzzle -- but you need to learn how the pieces - in this case the molecules - fit together to form th
Contact: Steve Roy
NASA/Marshall Space Flight Center News Center