title: Regulatory properties of 14 day embryo and adult hen heart AMP-deaminase.
abstract: Chromatography on phosphocellulose column revealed changes in the elution profile of chicken heart AMP-deaminase during ontogenesis. The extracts from the heart of adult hen and 14 day-old embryo displayed a single peak of the enzyme activity at a slightly different elution volume, whereas in the heart extract of 1 day-old chicken two molecular forms of adenylate deaminase have been eluted. The kinetic and regulatory properties of the purified adult hen heart AMP-deaminase were studied and compared with those of the corresponding enzyme from 14 day-old embryo heart. Both enzymes exhibited a slightly sigmoid-shaped plot of the reaction rate versus substrate concentration, which shifted to hyperbolic form when ATP or ADP were added into the incubation medium. The enzymes were strongly activated by ATP, less efficiently by ADP and the activatory effect was enhanced at low substrate concentration. Orthophosphate inhibited both enzymes but this inhibition was more potent for the embryo heart enzyme. Palmitoyl-CoA inhibited adult hen but not the embryo heart AMP-deaminase. The data presented indicate that the differences also in the regulatory properties of the molecular forms studied do exist and correspond with the ontogenetic differences observed previously (Kaletha and Skladanowski (1981) Experientia 37, 232-234) concerning the effect of temperature on the chicken heart adenylate deaminase.
mesh_terms: D000659:AMP Deaminase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002642:Chick Embryo; D002645:Chickens / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D066298:In Vitro Techniques; D007700:Kinetics; D009206:Myocardium / Q000201:enzymology*; D009709:Nucleotide Deaminases / Q000378:metabolism*; D010171:Palmitoyl Coenzyme A / Q000494:pharmacology; D010710:Phosphates / Q000494:pharmacology
chemical_list: D010710:Phosphates; D010171:Palmitoyl Coenzyme A; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D009709:Nucleotide Deaminases; D000659:AMP Deaminase