Jacob Shaner, Brigham Young University
Medical and biological research depends on successful protein detection. One method of protein detection is by mass spectrometry, where the proteins are detected according to their mass and charge. Mass and charge result in a mass to charge ratio (m/z). This method is simple and effective because it requires extremely small amounts of sample and can run hundreds of experiments over the course of an hour. One limitation in using mass spectrometry for protein research is caused by the large molecular mass of proteins. Protiens have large molecular weights, such as ~12,000 grams per mole for cytochrome c, in comparison to other ions, such as 85 grams per mole for rubidium ion. Mass spectrometers have less accurate measurements at when the m/z ratio is large. Increasing the charge, however, allows protein ions to be detected at lower m/z ratios and can result in more accurate measurements. Our project focuses on using additives in the solvent sprayed to increase the charge state on the protein when it is sprayed, also called supercharging. This will allow the protein to obtain greater resolution and signal in mass spectrometers. This would increase the effectiveness of research on proteins that have medical and biologically important applications, such as curing Alzheimer’s, fighting cancer, and combating diabetes. In our experiments, we will be using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR-MS) coupled with Electrospray Ionization (ESI). Solutions containing proteins, potential supercharging additives, and a supporting solvent will be sprayed from a small capillary against a charged plate, which will generate protein ions in the gas phase. This is ESI. The ions will then enter the mass spectrometer and spin within the electromagnetic field generated by a cyromagnet, and then the observed m/z ratios will be Fourier transformed. This is FTICR. The types and concentrations of proteins and additives will be to test the effectiveness of different additives on different proteins. In a lab in California, it was observed that using smaller glass tips for electrospray resulted in higher charge states for the proteins sprayed. This leads us to expect that adding silicate to the solutions will have a similar effect. We also anticipate that other potential additives will be found and can then be used as well.