Enzymes (isoenzyme system) as homeostatic mechanisms the isoenzyme (ADA2) of adenosine deaminase of human monocytes-macrophages as a regulator of the 2'deoxyadenosine.
Regarding homeostatic mechanisms in the enzyme (isoenzymes) and substrate system we show through a simulation model obtained by STELLA II software that: (i) a pair of isoenzymes (Is1 and Is2) that have different affinity for the substrate (Is2 affinity < Is1 affinity), can constitute an efficient homeostatic mechanism: by varying the relative concentration of the isoenzymes in the system, the levels of the substrate can be controlled; (ii) the isoenzymes ADA1 and ADA2 of adenosine deaminase (ADA) that have different affinity for the substrate 2'deoxyadenosine (ADA2 has very weak affinity for 2'deoxyadenosine) constitute, inside human Monocytes-Macrophages, a homeostatic mechanism that assures an up-regulation of 2'deoxyadenosine and a down-regulation of a second substrate (adenosine) for which the affinity of the two isoenzymes is similar.
Gakis
C
C
Clinic of Infectious Diseases, University of Sassari, Italy.
Cappio-Borlino
A
A
Pulina
G
G
D000241:Adenosine / Q000378:metabolism; D000243:Adenosine Deaminase / Q000378:metabolism*; D003198:Computer Simulation; D003839:Deoxyadenosines / Q000378:metabolism*; D006706:Homeostasis; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D007700:Kinetics; D008264:Macrophages / Q000201:enzymology / Q000378:metabolism*; D008954:Models, Biological; D009000:Monocytes / Q000201:enzymology / Q000378:metabolism*; D012984:Software
D003839:Deoxyadenosines; D007527:Isoenzymes; D000243:Adenosine Deaminase; D000241:Adenosine; C058118:2'-deoxyadenosine