One of the experiments astronauts will perform when the shuttle docks with the Russian space station Mir involves protein research by Jeffrey O. Boles, an assistant chemistry professor at Tennessee Technological University, and Gerard Bunick of the Oak Ridge National Laboratory Structural Biology Division. The work may help answer crucial questions posed by scientists searching for better treatments for many diseases.
In basic terms, the experiment involves crystallizing proteins attached to DNA strands. The process will allow scientists to make a three-dimensional model of the proteins to study for medical research. Until now, these proteins have resisted the probing eye of science. Crystallizing proteins for research on earth is hampered by gravity, causing crystals to be hollow or thin. By performing the experiment in the microgravity of a space station, larger protein crystals can be grown and then returned to earth.
Proteins are responsible for many functions, Boles says, including helping transmit nerve impulses to our senses, maintaining cell structure, fighting disease and attaching to DNA.
"But there are two roadblocks to understanding their three-dimensional structures," says Boles. "The first is crystallization, which we can solve in space. The second roadblock is that the elements normally present in proteins are too 'light' to be useful using the current technology for determining 3-D structure."
And that's where Boles' research comes into play. He has developed a way to make the proteins heavier by adding heavier atoms without changing the protein's original structure.
"I trick Mother Nature," says Boles. "I give her an unnatural amino acid, a substitute of heavier atomic weight, that's so close to the original that I can make her put it in the protein."
The resulting "mutant protein" is otherwise structurally identical to its natural counterpart. At Oak Ridge, Bunick's research team has incorporated the altered protein into a unique strand of DNA. The result has been placed into what NASA calls a "crystallization button," in which the DNA is expected to grow into a sturdy crystal.
Once the crystal is brought back to earth, it will be X-rayed, and a computer will try to map the crystal's molecular structure. Which means that for the first time, scientists will be able to get a close look at these proteins. Which, in turn, will provide long-sought-after information for research on cancer and other diseases.
Boles' novel approach -- modifying the proteins' atomic weight -- to this long-standing problem secured him National Science Foundation funding several years ago, as well as a 1995-96 Oak Ridge Associated Universities' Young Faculty Enhancement Award and a 1995 Outstanding Young Alumnus Award from Tennessee Tech.
All systems are go for the estimated 4:27 a.m. Sunday launch of Atlantis from the Kennedy Space Center in Cape Canaveral, Fla. The experiment will be retrieved during another shuttle mission in April or May.