Applications of Field-Cycling NMR to Studies of Biomolecules

点击翻译按钮获取中文摘要

DESCRIPTION (provided by applicant): We wish to continue collaborative biological research demonstrating and utilizing the capabilities of our field-cycling device for use in shared commercial instruments. Our pneumatic device is relatively simple and is intended to be used in a variety of commercially available instruments, perhaps eventually at many other laboratories in some commercial form or as copies. Widely used commercial instruments are designed to work at some fixed field, where, for example, the sample's proton spins resonate at frequencies such as 500, or 600 MHz. Our new device allows researchers to program these experiments so that samples spend key parts of the time in lower fields, down to almost the earth's magnetic field. From this capability we get a better idea about time-scales and amplitudes of random-seeming motions in these molecules than cannot otherwise be obtained experimentally. In some cases these motions are key to their biological activity, while in others they may regulate these activities. Our results can then be used to help understand biochemical activity of enzymes, or to help validate computer simulations of their dynamics. Our device may also be useful for development of drugs, by helping to locate unknown activities in proteins, and their location in the structure. It has been applicable to a wide variety of molecules so far, including a short DMA duplex, an enzyme, and several phospholipids in membranes. Our plans include a major continuation of work (with Prof. Mary Roberts, Boston College) on membranes and how they interact with phospholipases; and several projects involving other collaborators, on several other enzymes. We will obtain new information about physical arrangements in these systems, and especially about dynamics of small molecules (substrates and inhibitors) weakly bound to enzymes.