Differences of adenosine kinases from various mammalian tissues

1. Adenosine kinases purified to homogeneity from various mammalian tissues have a monomeric structure, and their molecular weights were estimated around 40,000. 2. The enzyme activity per wet weight of tissue appears to vary from source to source, but the specific activities of the final enzyme preparations were alike, which were 6.3--7.8 mumol/min/mg protein. 3. No or small difference was observed in the kinetic properties among all seven adenosine kinases. 4. Some differences in structure were observed among five liver enzymes from human, rabbit, rat, mouse and Mongolian gerbil, but no difference was observed between the enzymes from human placenta and liver, or the enzymes from rat liver and brain.