title: Demonstration of plasma-membrane adenosine diphosphatase activity in rat lung.
abstract: The adenosine diphosphatase (ADPase) activity of rat lung has been investigated. Subcellular fractionation of lung tissue homogenates by sucrose density gradient centrifugation has shown the ADPase activity to be associated with the plasma membrane. ADPase was solubilised from the membranes and fractionated by ammonium sulphate precipitation to separate a specific, low-Km ADPase from non-specific alkaline phosphatase activity. The solubilised ADPase has a Km of 50 microM at pH 7.5 and appears to be distinct from ATPase.
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000032:analysis; D000262:Adenylyl Cyclases / Q000032:analysis; D000266:Adenylyl Imidodiphosphate / Q000494:pharmacology; D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D001081:Apyrase / Q000032:analysis*; D002462:Cell Membrane / Q000201:enzymology; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008168:Lung / Q000201:enzymology*; D010744:Phosphoric Monoester Hydrolases / Q000032:analysis*; D051381:Rats
chemical_list: D000266:Adenylyl Imidodiphosphate; D000244:Adenosine Diphosphate; D000469:Alkaline Phosphatase; D010744:Phosphoric Monoester Hydrolases; D000251:Adenosine Triphosphatases; D001081:Apyrase; D000262:Adenylyl Cyclases