Some properties of rat myocardial ornithine decarboxylase and the in vitro effects of nucleotides.
Myocardial ornithine decarboxylase appears to have characteristics similar to those of enzymes isolated from other tissues. Ornithine decarboxylase activity decreased very rapidly after the death of the animal. Storage of the cell sap fraction at 0 degrees C or -15 degrees C, however, led to only a small decrease in the enzyme activity up to 3 days after preparation. Pyridoxal phosphate at an optimum of 50 muM was essential for full enzyme activity. Thiol compounds did not increase the myocardial ornithine decarboxylase enzyme activity. The subcellular distribution of the enzyme in the myocardium was found to be different from that reported in other tissues. A partial purification of the enzyme was possible using the proteins precipitated at pH 5 from a cell-soluble fraction or by passing a soluble fraction through a Sephadex G 100 gel column. ATP, ADP, and AMP inhibited ornithine decarboxylase at high concentrations (5 mM), but GTP, CTP, and ITP inhibited at a 1 mM concentration and above.
D000227:Adenine Nucleotides / Q000494:pharmacology; D000818:Animals; D002262:Carboxy-Lyases / Q000378:metabolism*; D000242:Cyclic AMP / Q000494:pharmacology; D004355:Drug Stability; D005615:Freezing; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009206:Myocardium / Q000201:enzymology*; D009955:Ornithine Decarboxylase / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism; D011732:Pyridoxal Phosphate / Q000494:pharmacology; D051381:Rats; D012265:Ribonucleotides / Q000494:pharmacology*; D013347:Subcellular Fractions / Q000201:enzymology
D000227:Adenine Nucleotides; D012265:Ribonucleotides; D011732:Pyridoxal Phosphate; D000242:Cyclic AMP; D011494:Protein Kinases; D002262:Carboxy-Lyases; D009955:Ornithine Decarboxylase