Grant: Research Tools and Instruments - Category 1 (<$150,000)

Proteins perform various biological functions including those that are structural (e.g., spider silk), that accelerate chemical reactions (enzymes), and those that transport fatty compounds in the blood. These proteins are often folded into discrete units which interact with each other to form complex (multimeric) structures: dimers (2 units), trimers (3 units), tetramers (4 units), etc. Dr. Bearne studies two enzymes that form such structures. The enzyme CTP synthase catalyzes the formation of a building block for genetic material and is a recognized target for the development of anticancer drugs. This enzyme exists as both an inactive dimer and an active tetramer. Dr. Bearne is developing compounds to inhibit this enzyme and needs to assess if the inhibition occurs because the compounds block tetramer formation. He is also studying the enzyme glutamate racemase that catalyzes the formation of a building block of bacterial cell walls, making it a target for the development of antibacterial drugs. Dr. Bearne has discovered compounds that prevent this enzyme from forming active dimers. This enzyme is not amenable to traditional methods of assessing its multimeric state. The requested macroIon Mobility Spectrometer (IMS) will provide a sensitive and rapid technique to monitor the multimeric state of these two enzymes and facilitate inhibitor development. Dr. Liu has developed a new method to produce artificial spider silk - a material that may find medical uses in wound dressings and sutures, and as scaffolds for tissue regeneration. An IMS will permit Dr. Liu to assess how these proteins assemble before forming silk and, because of the fast response time of the IMS, he will be able to study the assembly process in real time. Dr. McLeod studies the assembly of proteins with dietary fats in the liver and an IMS will allow him to measure the size of these complexes, which seems to be related to their ability to cause cardiovascular disease. The low sample requirement and high sensitivity of the IMS will allow Dr. McLeod to efficiently utilize the precious and limited blood samples he obtains in the lab. He will also use the IMS to measure the sizes of protein complexes formed in fat cells that are important in some forms of diabetes.