Electrochemical and spectroscopic studies of a molybdenum cofactor model in aqueous micellar solution
A model of the molybdenum cofactor (Mo-co) of the molybdenum hydroxylases is examined in a variety of solvent environments that enhance the enzyme-mimetic properties of the complex. The complex MoO2(1L), 1, where 1L = N,N'-dimethyl-(N,N'-bis(2-mercaptophenyl)-1, 2-diaminoethane), has been studied by cyclic voltammetry and infrared spectroscopy in DMF and in aqueous micellar solution as a function solvent composition and of pH (see structure, Figure 1). As the DMF concentration is lowered and replaced by aqueous micellar solution, E(1/2) values become more positive. In 95% aqueous micellar solution, the complex exhibits quasi-reversible electrochemistry. As the pH is decreased from 9 to 4, the E(12) values for 1 become more negative. The IR asymmetric stretch of the Mo-oxo bond in 1 increases in frequency with decreasing pH. The relevance of this work to the understanding of molybdenum hydroxylase enzymes is underscored, and the effectiveness of solubilization of complexes in micellar solutions is discussed.
Waldron, Kimberley A. and Topich, Joseph, "Electrochemical and spectroscopic studies of a molybdenum cofactor model in aqueous micellar solution" (1997). Regis University Faculty Publications. 1251.