MULTIDIMENSIONAL NUCLEAR-MAGNETIC-RESONANCE METHODS TO PROBE METAL ENVIRONMENTS IN PROTEINS

This chapter discusses methods to obtain information about metal sites in proteins by means of nuclear magnetic resonance (NMR) techniques. NMR spectroscopy has developed into a powerful method to study structures both of metal environments in proteins and of proteins in general. The application of NMR in chemistry and biochemistry is discussed in the chapter. An introduction to general NMR methodology used for protein structure determination is also presented. The chapter also discusses the structure of metal environments in proteins. The use of pH variations to identify metal ligands, techniques to probe the environment of a metal inside a protein for paramagnetic and diamagnetic metal ions, and extrinsic ligands are described. It discusses time-dependent phenomena—namely, conformational equilibria, NH exchange rates, and NMR relaxation times. It also focuses on probing the oxidation state of a metal site and changes thereof. Finally, modeling metal sites in proteins is also presented in the chapter. © 1993, Elsevier Inc. All rights reserved.