This is an in-class PDB exercise based on the paper "Mechanisms Controlling the Cellular Metal Economy" by Gilston and O'Halloran. Students are asked to visualize the metal binding sites of several proteins discussed in the paper, highlighting unusual metal geometries. After identifying the amino acid residues involved in metal binding, students will discuss the bond structure in terms of HSAB theory. 

This activity is designed to give students a deeper understanding of what post-translational modification does in a metalloenzyme using nitrile hydratase (NHase) as a model system.  The metallo-active site of NHase contains a cobalt(III) center that is bound to an unusual coodination sphere containing bis-amidate, cysteinate, sulfenate (RSO^-), and sulfinate (RSO₂^-) ligands.

31-P NMR spectrum of alpha-dodecatungstophosphoric acid is a combination of thirteen spectra, each spectrum representing the compound with a different number of ¹⁸³W isotopes per molecule. In order to fully interpret the spectrum one needs to apply binomial distribution to calculate the mole fractions of the molecules with various numbers of ¹⁸³W isotopes.

This LO requires an understanding of the satellites concept in NMR spectroscopy, originating from coupling with nuclei whose NMR active isotopes are not 100% abundant.