We study mechanisms of action of enzymes requiring pyridoxal 5'-phosphate, including amino acid decarboxylases, transaminases, and dehydratases. We are particularly interested in the binding of the coenzyme to various enzymes and in minor reaction pathways which may result in enzyme inactivation. In our studies we use nmr, kinetics, isotope effects, equilibrium binding, coenzyme analog inhibitors, stereochemistry, isotope labelling, and a variety of other techniques. BIBLIOGRAPHIC REFERENCES: "Abortive Reactions of Dopa Decarboxylase," R.L. Baughn and M.H. O'Leary, Federation Proc., 35, 1749 (1976). "13C NMR Spectroscopy of Labeled Pyridoxal 5'-Phosphate", M.H. O'Leary and J.R. Payne, J. Biol. Chem., 251, 2248 (1976).