title: Purification and properties of a nucleoside triphosphatase from Sinclair swine.
abstract: A nonspecific nucleoside triphosphatase was partially purified from skin and cutaneous melanoma tumors from Sinclair swine using chloroform precipitation, hydrophobic, ion-exchange and affinity chromatography techniques. The enzyme was not stimulated by Na+, K+ or Mg2+ but it was inhibited by EDTA. The enzyme was not inhibited by quercetin, proflavin, azide or ovabain. The enzyme exhibited optimal activity over a pH range of 8-9 and the activation energy was 10.4 and 9.8 kcal/mol for dUTP and ATP, respectively. The apparent Km of the enzyme for dUTP and dTTP was approximately 20 mumol/l while the apparent Km for dATP, ATP, dCTP, CTP and UTP was in the range of 65-80 mumol/l.
mesh_terms: D000818:Animals; D007700:Kinetics; D008545:Melanoma / Q000201:enzymology*; D043583:Nucleoside-Triphosphatase; D010744:Phosphoric Monoester Hydrolases / Q000037:antagonists & inhibitors / Q000302:isolation & purification*; D012867:Skin / Q000201:enzymology; D012878:Skin Neoplasms / Q000201:enzymology*; D013552:Swine
chemical_list: D010744:Phosphoric Monoester Hydrolases; D043583:Nucleoside-Triphosphatase