Regulation of the shikimate pathway of carrot cells in suspension culture [3-deoxy-D-arabino-heptulosonate 7-phosphate synthase activity changes]

The activity of the first enzyme of the shikimate pathway, 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase, is demonstrated in extracts of Daucus carota cells grown in suspension culture. Maximum specific enzyme activity is found midway through the logarithmic growth of the culture; cells in lag and stationary phases of growth have lower enzyme levels. The enzyme is activated by tyrosine and tryptophan. The extent of activation varies during cell growth.