Grant: Research Tools and Instruments

<p>&nbsp;</p> My research group is interested in proteins and lipids. Proteins are one of the major classes of biological macromolecules that fulfill chemical and structural tasks within living cells. Lipids are poorly water-soluble compounds that play numerous roles in cellular health and function. Some vitamins, such as vitamin E (tocopherol), are known as neutral lipids. Phospholipids are an abundant class of cellular lipids that make up biological membranes. Theses membranes surround each cell and the organelles within cells. Since the lipids and membranes are largely insoluble in water (they are hydrophobic) then cells face a problem when it comes time to move a lipid from one place to another across the mostly water-filled volume of a cell. To accomplish this task, nature has provided cells with lipid transfer proteins that ferry poorly water-soluble compounds from one membrane to another. How these proteins know what lipid to hold on to, and what membrane to find that lipid in or deliver it to, is the focus of our work. <br /> <br /> One of the key steps in a lipid transfer protein doing its job is being able to stick to a phospholipid membrane. We know now that certain membranes contain phospholipids that attract proteins to their surface. The curved shape of some membranes is what signals lipid transfer proteins to stick to them. Measuring the ability of proteins to stick to phospholipid membranes is necessary if we are to understand the movement of these proteins and their cargos. The instrument requested in this proposal is able to do just that.<br /> <br /> In the past we have accomplished these measurements with a device called a Dual Polarization Interferometer (DPI), a surface chemistry technique. In brief, we first adsorb a phospholipid membrane on a sensor chip then flow protein across this layer. The instrument then measures how much protein sticks to the membrane. <br /> <br /> Our DPI instrument has entered its final days of operation. It failure is destined by the complete withdrawal of support by the manufacturer, including all consumables. The new device, a Reichert Technologies Dual Channel Surface Plasmon Resonance System (SPR) can measure the same phenomena and fulfills all of our research needs. It will allow us to not only measure how much and how well proteins stick to phospholipid membranes, but also how fast they stick and how fast they fall off. Both of these events (sticking and falling off) are important criteria for a successful lipid transfer protein. We are confident that the SPR system will advance our research program and help us untangle the mysteries of how cells move lipids from one place to another.