Crystals grown on the International Space Station could be used by researchers back on Earth to develop new drugs to help fight disease. To explore this further, NASA will soon conduct a series of investigations to explore how these crystals form, and how this could ultimately benefit us.
When developing new drugs, researchers often look at the exact shape of the protein they need to target, and then in effect reverse engineer the drug. This is known as structure-based drug design. Yet to achieve this you first have to figure out exactly what the protein in question looks like, and the finer the detail, the more precise the drug can be.
To determine the ins and outs of a protein's structure, researchers use a method in which the molecules are grown in crystals. This allows them to map the 3D nature of the proteins using X-ray beams. However, there some limitations to growing the crystals on Earth, which is why researchers think that growing them on the International Space Station in microgravity could produce more precise results.
A lysozyme crystal formation as seen under a light microscope. Lawrence DeLucas
“When you purify proteins to grow crystals [on Earth], the protein molecules tend to stick to each other in a random fashion,” explains Lawrence DeLucas, the primary investigator of the project to grow protein crystals in space. “These protein aggregates can then incorporate into the growing crystals causing defects, disturbing the protein alignment, which then reduces the crystal's X-ray diffraction quality.”
On the ISS, however, it has been found that the protein crystals produced frequently contain fewer of these imperfections. It is thought that the microgravity slows the growth of the crystals, which means that the aggregates of proteins that form the defects are not incorporated into the crystals, thus giving a much purer sample of the proteins.
This latest study will investigate these reasons further and try to better understand why certain proteins form purer crystals under the influence of microgravity, while others do not. In these cases, it is thought that the shapes of the proteins in question may have an influence on how the crystals grow, and this investigation will try and figure out why exactly that is.
It is hoped that by knowing which proteins will benefit from being grown in space, scientists can then maximize the scarce resources that it takes to send proteins up and grow the crystals in space.