Properties of Choline and Ethanolamine Kinases Paritally Purified from Rat Liver Supernatant.

Choline and ethanolamine kinases were partially purified from rat liver homogenate by 30 fold and 20 fold, respectively. Though the separation of two enzymes were not achieved, some properties were observed the suggesting possibility that different enzymes or active centers are involved in the phosphorylation of choline and ethanolamin. An apparent Michaelis constant (Km) for choline was 0.23 mM and for ethanolamine was 5mM. Both enzymes showed nearly the same values of maximal velocities or Km for ATP. However, some structural analogues of choline or ethanolamine affected choline and ethanolamine kinase activities in somewhat different manners.