Last Week in Toronto

This past week was my last week in the Gingras lab in Toronto. It’s been very valuable to learn about mass spectrometry in such a high-throughput proteomics lab. Hopefully, Ashley and I will continue working on these experiments back at W&M. We went up to Toronto because Dr. Hinton has been collaborating with Dr. Gingras since 2016 to further uncover the pathway of MK-STYX and the roles of pseudophosphatases. They also have multiple mass spectrometers– equipment we don’t have access to in Williamsburg. In our last few days in Canada, we learned about BioID, a process used to identify proteins that interact with or come into close proximity to a specific protein of interest. With BioID, you attach a biotin ligase (an enzyme that biotinylates proteins or covalently attaches biotin) to the protein you’re interested in. The enzyme used is altered so that it “promiscuously” biotinylates surrounding proteins. Essentially, it releases a cloud of activated biotin, and proteins nearby are biotinylated. You can then isolate these proteins by using beads that strongly bind biotin and identify what the proteins are using a mass spectrometer. In a mass spectrometer, proteins in a sample that is injected are ionized into peptides, which are then searched through a database to identify what proteins are present. Through this, you are able to see what proteins your protein of interest interacts with or what environment it acts in. With affinity purification, less harsh washes are used in sample preparation to pull down directly interacting protein complexes rather than all proteins in the vicinity. This gives you more specific information as to what proteins your protein directly interacts with. Once the stable cell lines are ready (probably by the beginning of the fall semester), we plan to help prepare samples here at W&M for processing in Toronto. I’ve learned a lot over the past few weeks, both culturally and academically, and it’s been a great experience to see how research is done outside of the US in a professional lab setting.