Students in Structural Biology, a course taught by Dr. Rebecca Roberts, have spent the last four weeks growing crystals made out of proteins. Structural Biology is the study of the three-dimensional shape of biology molecules, such a proteins and DNA, and how the shapes are related to the function of the molecules. Such structure-function relationships are important not only on the molecular level, but are just as important for everyday items such as a chair — it has a seat, a back, and four legs to form a stable surface for sitting.
One way to analyze the shape of a protein is to stack it together into a crystal and then shoot high-powered x-rays at the crystal. The crystal form acts as an amplifier and causes the x-rays to scatter. The resulting scattered pattern of x-rays (called a diffraction pattern) can then be used to deduce the shape of the protein in the crystal.
Students in the course generated their own crystals and learned about the theory and practical issues surrounding this difficult process. Their experience culminated in a visit to the Glaxo Smith Kline facility near Collegeville, where they were brought through the process from beginning to end. Dr. Angela Smallwood of GSK organized the visit. The students started in the expression facility, learning how target proteins are generated
in high enough quantities to make crystals. They moved on to see how robotics are used to facilitate crystal growth and analysis. One student commented “Dr. Roberts, so much of the hands on work we’ve been learning in lab is done by robots here!”
The students watched as Dr. Smallwood caught a microscopic protein crystal in a small metal loop and centered it on the x-ray diffractor. The visit ended with the students donning 3-D glasses and travelling through a protein structure in three dimensions – focusing in on how a drug binds to a target protein.