I am writing this proposal in order to obtain support to begin a midcareer transition in my research focus. I am a classically trained biochemist with an expertise in the areas of cell biology and neurochemistry. Ultimately, my goal is to become trained in the rapidly growing field of protein mass spectrometry so that I can 1) begin to examine the biochemical system that I have been studying for 12 years in new and exciting ways, 2) collaborate with my colleagues on proteomics projects that will further their research programs, and 3) train undergraduate students in the state-of-the-art technique. Since protein mass spectrometry is a complex analytical chemistry technique that requires a knowledge base that is very different from my training and current research expertise, I anticipate that this transition will take at least three years. In this proposal, I am specifically seeking support to initiate a collaborative project with a mass spectrometry expert at Notre Dame so that I can begin to learn how to operate a mass spectrometer and gain experience analyzing the data. I also propose to attend a conference and short course focused on protein mass spectrometry. Thus, when completed, I will have enough expertise to pursue funding from other grant agencies to purchase a mass spectrometer and to use this technique to answer important biological questions.