title: A kinetic study of the rat liver adenosine kinase reverse reaction.
abstract: Adenosine kinase is an enzyme catalyzing the reaction: adenosine + ATP --> AMP + ADP. We studied some biochemical properties not hitherto investigated and demonstrated that the reaction can be easily reversed when coupled with adenosine deaminase, which transforms adenosine into inosine and ammonia. The overall reaction is: AMP + ADP --> ATP + inosine + NH(3). The exoergonic ADA reaction shifts the equilibrium and fills the energy gap necessary for synthesis of ATP. This reaction could be used by cells under particular conditions of energy deficiency and, together with myokinase activity, may help to restore physiological ATP levels.
authors.affiliation: Dipartimento di Medicina Interna, Sc. Endocrino-Metaboliche e Biochimica, Università di Siena, Siena, Italy. vannoni@unisi.it
authors.forename: D
authors.initials: D
authors.lastname: Vannoni
authors.forename: S
authors.initials: S
authors.lastname: Giglioni
authors.forename: A
authors.initials: A
authors.lastname: Santoro
authors.forename: E
authors.initials: E
authors.lastname: Aceto
authors.forename: E
authors.initials: E
authors.lastname: Marinello
authors.forename: R
authors.initials: R
authors.lastname: Leoncini
mesh_terms: D000241:Adenosine / Q000378:metabolism; D000243:Adenosine Deaminase / Q000378:metabolism; D000248:Adenosine Kinase / Q000378:metabolism*; D000641:Ammonia / Q000378:metabolism; D000818:Animals; D007288:Inosine / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D051381:Rats; D013379:Substrate Specificity
chemical_list: D007288:Inosine; D000641:Ammonia; D000248:Adenosine Kinase; D000243:Adenosine Deaminase; D000241:Adenosine