title: Dinucleoside tetraphosphatase from human blood cells. Purification and characterization as a high specific activity enzyme recognized by an anti-rat tetraphosphatase antibody.
abstract: Dinucleoside tetraphosphatase (Np4Nase; EC 3.6.1.17) has been purified 170,000-fold from a 30-60% ammonium sulfate fraction of a human blood cell extract. Purification included a dye-ligand affinity elution step using the inhibitor adenosine 5'-tetraphosphate. Human blood Np4Nase resembled rat liver Np4Nase, including recognition by anti-rat Np4Nase, but differed from homogeneous human leukemia Np4Nase in the 1000-fold lower specific activity of the latter. The results are discussed in relation to the potential role of diadenosine tetraphosphate (Ap4A) in the control of cell division and the turnover of Ap4A in blood.
authors.affiliation: Departamento de Bioquimica y Biología Molecular y Genética, Facultad de Medicina, Universidad de Extremadura, Badajoz, Spain.
authors.forename: R M
authors.initials: RM
authors.lastname: Pinto
authors.forename: M J
authors.initials: MJ
authors.lastname: Costas
authors.forename: A
authors.initials: A
authors.lastname: Fernández
authors.forename: J
authors.initials: J
authors.lastname: Canales
authors.forename: J A
authors.initials: JA
authors.lastname: García-Agundez
authors.forename: J C
authors.initials: JC
authors.lastname: Cameselle
mesh_terms: D017766:Acid Anhydride Hydrolases; D000227:Adenine Nucleotides / Q000494:pharmacology; D000818:Animals; D006801:Humans; D015151:Immunoblotting; D008099:Liver / Q000201:enzymology; D015636:Magnesium Chloride / Q000494:pharmacology; D010744:Phosphoric Monoester Hydrolases / Q000037:antagonists & inhibitors / Q000097:blood*; D051381:Rats; D012969:Sodium Fluoride / Q000494:pharmacology; D015032:Zinc / Q000494:pharmacology
chemical_list: D000227:Adenine Nucleotides; D015636:Magnesium Chloride; C017991:adenosine 5'-tetraphosphate; D012969:Sodium Fluoride; D010744:Phosphoric Monoester Hydrolases; D017766:Acid Anhydride Hydrolases; C020023:bis(5'-nucleosyl)tetraphosphatase (asymmetrical); D015032:Zinc