Multiple forms of glucokinase from Dictyostelium discoideum.

A single form of glucokinase with an apparent Km value equal to 0.12 mM glucose was detectable in extracts prepared from aggregating cells, whereas kinetic and electrophoretic evidence indicated the presence of this form as well as a second glucose-phosphorylating enzyme with a Km value of about 0.01 mM glucose in extracts from culminating cells.