Photo: Harry Dailey, professor of microbiology.
Photo: X-ray crystallographer B.C. Wang has previously grown crystals in the space shuttle Columbia.
By Phil Williams
An important enzyme being studied by scientists at the university is currently aboard Mir, the Russian space station.
Crystals of the enzyme, ferrochelatese, were delivered to Mir by the space shuttle Endeavour when it docked with Mir earlier this month. The crystals were grown in the zero-gravity environment of the shuttle; they will remain on Mir for four months.
Interesting enzyme
"This is a really interesting enzyme from an evolutionary standpoint," says Harry Dailey, professor of microbiology.
The enzyme directs the insertion of iron into a compound called protoporphyrin to make heme, an important non-protein component of hemoglobin. Dailey has studied the action of ferrochelatase for years and has isolated it from humans, chickens, rats, frogs, mice and fruit flies.
On this project he is working with B.C. Wang, an X-ray crystallographer at UGA who has previously sent crystals aloft in the space shuttle Columbia, and with his associate John Rose and graduate student Edward Wu.
Photo: Harry Dailey, professor of microbiology.
"The enzyme was actually discovered in the 1950s, but we isolated the first mutant that did not have it, so we were the first to prove it was actually an enzyme working in the mammalian system," says Dailey.
Understanding the structure of proteins is crucial to knowing how they work, and crystals grown in space are far more "orderly" than those grown under conditions of gravity on Earth.
"We have already been able to produce a crystal of this enzyme, but growing it in space will allow us to have one at a much greater resolution," Wang explains.
When the crystals have returned from Mir, they will be studied at UGA using X-ray crystallography, which might be thought of as a kind of microscope that allows far greater resolution than light microscopy, enabling scientists to see atoms. When crystals are grown in a more orderly way, it's as if another turn of the focus knob suddenly brings the molecule into dazzling, razor-sharp focus.
