Isolation and Immunological Properties of Adenosine Kinase

Bovine liver adenosine kinase is a 43 kDa protein that catalyzes the transfer of phosphate from GTP or ATP to adenosine. Its immunological properties were compared to other GTP-binding proteins of ∼ 40 kDa, in particular those involved in signal transduction, such as G s and G i , the stimulatory and inhibitory regulatory proteins of adenylyl cyclase, G t , from the visual excitation system, and G o , a similar protein of unknown function. Antibodies elicited in rabbits against adenosine kinase did not significantly cross-react with other guanyl nucleotide-binding proteins. Antibodies against the other GTP-binding proteins did not react with adenosine kinase. Thus these GTP-binding proteins do not exhibit immunological cross-reactivity.