Carbohydrate-derived Organoselenium Compounds: Synthesis and Application in the Structural Analysis of Biomolecules
This chapter deals with the synthesis of the carbohydrate-derived organoselenium compounds and their utility in the structural analysis of biomolecules. The isotopic distribution and anomalous scattering properties of selenium encouraged chemists towards selenium chemistry and its incorporation into organic molecules. Selenium is ideal for anomalous scattering in multi-wavelength anomalous dispersion and single-wavelength anomalous dispersion of X-ray crystallographic analysis of biomolecules and proteins. Furthermore, the 77Se isotope is nuclear magnetic resonance (NMR)-active with the spin quantum number ½. Experimental resolution of the atomic structure of the proteins is advantageous, to understand molecular mechanisms as well as to fuel further research in drug development. In this regard, X-ray crystal analysis of selenium-incorporated proteins plays a vital role in the structural elucidation. Over two-thirds of the protein structures have been elucidated using this technique. This chapter summarizes the synthesis of carbohydrate-derived organoselenium compounds and the site-specific selenium derivatization of selenocarbohydrates, selenonucleosides and their chemical applications. X-ray crystallographic analysis and 77Se NMR spectroscopy are two powerful tools with which to analyse the 3-D structures of biomolecules in detail.