Fructokinases from developing maize kernels differ in their specificity for nucleoside triphosphates.

A new form of fructokinase has been identified from developing maize (Zea mays L.) kernels that utilizes CTP, UTP, and GTP from four to eight times more effectively than ATP at nonlimiting concentrations. Ten millimolar dithiothreitol was necessary to stabilize activity. A second form of fructokinase was nonspecific for nucleoside triphosphate whereas a third form was fairly specific for ATP.