AMP deaminase from the rat heart injured by high doses of vitamin D.
Adenylate deaminase (EC 3.5.4.6) has been isolated from the hearts of healthy rats and from the rats with cardionecrosis induced by administration of vitamin D in high doses. Crude extract from the necrotic hearts catalysed adenylate deamination with a higher maximum velocity and a higher apparent Km value than the extract from healthy hearts. The enzyme from healthy animals was activated by ATP (Km-type of activation); the maximum velocity of the ATP-activated enzyme could be increased in about 50% by preincubation with phosphatidylcholine-containing liposomes. Liposomes had no effect on the enzyme isolated from the hearts of vitamin D-intoxicated animals, whereas other kinetic and regulatory properties were similar to those of the enzyme from healthy hearts. Kinetic and regulatory parameters of adenylate deamination in the hearts of rats which survived cardionecrosis returned to normal values 6 weeks after vitamin D intoxication.
D000659:AMP Deaminase / Q000378:metabolism*; D000243:Adenosine Deaminase / Q000378:metabolism; D000818:Animals; D005260:Female; D006321:Heart / Q000187:drug effects; D007700:Kinetics; D009206:Myocardium / Q000201:enzymology* / Q000473:pathology; D009709:Nucleotide Deaminases / Q000378:metabolism*; D051381:Rats; D014807:Vitamin D / Q000506:poisoning*
D014807:Vitamin D; D009709:Nucleotide Deaminases; D000243:Adenosine Deaminase; D000659:AMP Deaminase