This proposal is for the addition of a quadrupole time-of-flight (Q-TOF) tandem mass spectrometer to the Biomolecular Mass Spectrometry Facility at the Medical University of South Carolina. The requested Q-- TOF instrument will be used primarily for analysis of peptide fragments of proteins isolated by gel electrophoresis with increased sensitivity, resolution, and mass accuracy compared to the existing instrumentation. The major user group represents a series of NIH funded research projects in which analysis of gel isolated proteins with high sensitivity is rate limiting. These projects include work on G protein-coupled receptor systems (vision, adrenergic receptors, thromboxane receptors, G proteins), IGF signal transduction, glucose transport systems, the gastric proton pump, and proteins interacting with dietary flavonoids. Many of these projects involve analysis of integral membrane proteins, an area which been addressed by relatively few mass spectrometry laboratories but one of particular interest and emphasis in the MUSC facility. The difficulties in analysis of integral membrane proteins necessitate higher mass spectrometric sensitivity than would normally be required for the same amounts of soluble protein in a sample. This fact, plus the fact that many of the proteins being addressed are also obtainable only in very small amounts, presents the need for state of the art instrument performance. The requested instrument will provide needed improved sensitivity as well as improved resolution and mass accuracy to facilitate solution of the major user group's research problems as well as contribute more generally to biological research via development of improved methodology for analysis of membrane proteins.
