It is planned to carry our equilibrium and kinetic studies of several unusual reactions of amino acids with pyridoxal or pyridoxal phosphate and metal ions as catalysts. The reactions will be followed spectrophotometrically or by nmr as a function of pH. Catalytic metal ions such as those of A1(III), Ga(III), and Zn(II) will be studied. The reaction rates of metal-free systems will be determined for specific Schiff base species in solution. Where possible, reaction rates of the metal-catalyzed system will be assigned to specific metal chelate compounds. It is planned to study the kinetics and mechanisms of the following reactions with the techniques described above: 1, elimination of electronegative groups from the Beta-carbon atoms of amino acids; 2, exchange (labilization) of hydrogen atoms in the Beta-positions of amino acids; 3, elimination of electronegative groups from the gamma-positions of amino acids; 4, dephosphonylation of 2-amino-3-phosphonopropionic acid; 5, oxygenation of tryptophane; and 6, decarboxylation of alpha keto and alpha amino acids containing carboxylate groups at the Beta-carbon atoms.
Szpoganicz, B; Martell, A E (1989) Comparative mechanisms of vitamin B6-catalyzed beta-decarboxylation and beta-dephosphonylation in model systems. Biochimie 71:591-7 |