The measurement of the equilibrium constant and the thermodynamic parameters of the binding of hydroxide ions to the active site of hemerythrin, an invertebrate iron containing protein, was done by a new difference spectroscopic method. The method enables accurate measurements of equilibrium constants without accurate knowledge of molar absorptivities or protein concentrations and is novel in that it takes the difference between the two equilibrium mixtures, thus enabling the measurement of equilibrium constants when it is not convenient or possible to produce either substance as a pure reference material.

Thesis (Ph. D.)--University of Chicago, Dept. of Chemistry, December 2003. / Includes bibliographical references. Also available on the Internet.

The amino acid sequence determination of Phascolopsis gouldii hemerythrin in the region of the proposed iron ligand at position 58 was the main objective of this research endeavor. Generation of a large peptide was pursued by trypsin digestion of citraconylated hemerythrin producing peptide 50-113 for sequenator analysis. Detection of the phenylthiohydantoin amino acid derivatives by gas-liquid and high-performance-liquid chromatography yielded unambiguous sequence elucidation through the region of interest identifying residue 58 as glutamic acid.