ABSTRACT
Early investigations of the Stickland reactions were performed with whole-cell suspensions of C. sporogenes. The characterization of these systems has been extensively reviewed by Nisman. In the review, emphasis will be on the enzymatic systems that catalyze the Stickland reactions, the physical and chemical properties of these enzymes, and their roles in energy metabolism. Catabolism of these mixtures involved the oxidation of a particular amino acid and the reduction of another as shown by the following general equation: This type of reaction became known as a Stickland reaction. By coupling each half reaction to the oxidation or reduction of dyes, such as benzyl viologen, methyl viologen, cresyl blue, and others as redox indicators, Stickland concluded that alanine, valine, and leucine served as hydrogen donors for C. sporogenes, whereas glycine, proline, and hydroxyproline were hydrogen acceptors in the coupled oxidation-reduction of amino acid pairs.
