Occurrence of dinucleosidetriphosphatase in the cytosol and particulate fractions from rat liver.
Dinucleosidetriphosphatase (EC 3.6.1.29) is present in both the 37,000 g rat liver supernatant and precipitate (50 mU/g each fraction). These two activities show matching molecular weights, isoelectric points, substrate specificities, Km values, bivalent cation requirements and inhibition by zinc (II). The particulate triphosphatase and a residual dinucleosidetetraphosphatase (EC 3.6.1.17) are solubilized by freeze-thawing or by Triton X-100. Detergent treatment also extracts an unspecific phosphodiesterase I activity (EC 3.1.4.1) which also splits dinucleoside polyphosphates. The above findings suggest the occurrence of cytosolic and particulate degradative pathways for dinucleoside polyphosphates.
D000818:Animals; D003600:Cytosol / Q000201:enzymology*; D006868:Hydrolysis; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008970:Molecular Weight; D043583:Nucleoside-Triphosphatase; D010744:Phosphoric Monoester Hydrolases / Q000032:analysis* / Q000302:isolation & purification; D051381:Rats; D013379:Substrate Specificity
D010744:Phosphoric Monoester Hydrolases; D043583:Nucleoside-Triphosphatase