PARAMAGNETIC LANTHANIDE(III) IONS AS NMR PROBES FOR BIOMOLECULAR STRUCTURE AND FUNCTION

摘要

Paramagnetic lanthanide(III) ions (Ln3+) have been used successfully as spectroscopic probes for the study of chemical, physical and physiological properties of many Ca2+-dependent biological systems in the past several years. Some paramagnetic Ln3+ (e.g. Pr-1+, Eu3+, and Yb3+) possessing very short electronic relaxation times are able to exhibit relatively sharp isotropically shifted lH NMR features attributable to the protons in the close proximity of the metal. Thus, the use of such Ln3+ ions as substitutes for Ca2+ in proteins raises the possibility of detailed NMR study of the Ca2+ binding environment in proteins. These paramagnetic Ln3+ ions have also been used as NMR probes for the study of the structural and functional roles of several metal-dependent antibiotics, such as the anthracyclines. We report in this contribution the use of two dimensional NMR techniques for the studies of paramagnetic Ln3+-substituted Ca2+ proteins in terms of the configuration of the metal-binding sites and the interactions with ligands. and for the study of metallo-antibiotics.