9723642 Curley The structure assignment of proteins as determined by modern NMR methods is greatly facilitated by access to appropriate regio- and stereoselectively labelled amino acids which can be incorporated into the proteins. Use of these labelled amino acids greatly increases experimental sensitivity and permits the use of isotope-edited NMR experiments which can provide specific structural information otherwise difficult to obtain. Of particular importance to assigning an accurate solution structure of a protein by NMR is stereospecific assignment of the amino acid side chain resonances. Useful for these assignments is access to amino acids with stereoselective substitution of deuteron for proton on the (-methylene groups of these amino acids with prochiral (-methylene protons. In addition, the effect of (-deuteration of the 13C relaxation rate will also facilitate C(carbon assignments, especially in large systems. A generalized, versatile, inexpensive method will be developed for the synthesis of virtually all the amino acids with prochiral (-methylene protons in a manner which will stereoselectively replace one of the prochiral protons with deuteron. These methods will also permit double labelling of the amino acid with 15N or 13C in a variety of patterns and can also be readily adapted to provide the natural amino acid L-isomer stereospecifically. Once obtained, these amino acids will be used to study biosynthesis and protein structure by NMR The function of proteins is dependent on their structure. Nuclear magnetic resonance (NMR) spectroscopy has become an important tool for determining the structure of proteins in solution. Proteins are composed of different amino acid building blocks which are bound together to make up the entire protein. The NMR study of proteins is made easier if the amino acids are labelled with nonradioactive, NMR-detectable isotopes. This project will develop general methods for the synthesis of these specially labelled amino acids. ***
