Reactions involving pyridoxal phosphate or pyridoxamine phosphate in the presence of metal ions. Part I. The reaction between pyridoxal phosphate and glutamate in the presence of cupric ions

Abstract

The reaction of pyridoxal phosphate with glutamate in the presence of cupric ions has been studied spectrophotometrically. At 25° and pH 4 the rate of formation of the copper–Schiff-base complex is first-order both in pyridoxal phosphate and in glutamate, but zero order in copper. We conclude that the presence of metal ions does not kinetically catalyse the formation of the Schiff base, but acts as a trap for both the Schiff base and an amino-alcohol intermediate.