title: Geometry-dependent phosphodiester hydrolysis catalyzed by binuclear copper complexes.
abstract: Two isomeric binuclear ligands PBTPA and MBTPA and their copper(II) complexes were prepared and examined for hydrolysis of a model phosphodiester substrate: bis(p-nitrophenyl)phosphate. A bell-shaped pH vs rate profile, which is in agreement with one mechanism proposed for bimetallonucleases/phosphatases, was observed for the binuclear complex of copper(II) and PBTPA. At pH 8.4, a maximum rate of 1.14 x 10(-6) s(-1)--more than 10(4)-fold over uncatalyzed reactions--was achieved. However, the analogous complex of MBTPA did not show significant rate enhancement. The binuclear complex of copper(II) and PBTPA also showed 10-fold acceleration over mononuclear complex of copper(II) and tris(2-pyridylmethyl)amine (TPA) catalyzed reaction. A phage phiX174 DNA assay showed that the complex of copper(II) and PBTPA promoted supercoiled phage phiX174 DNA relaxation under both aerobic and anaerobic conditions, in contrast to the hydrolytic inactivity of the mononuclear complex of copper(II) and TPA.
authors: Department of Chemistry, New York University, New York, New York 10003, USA.
authors: Lei
authors: L
authors: Zhu
authors: Osvaldo
authors: O
authors: dos Santos
authors: Chi Wan
authors: CW
authors: Koo
authors: Marc
authors: M
authors: Rybstein
authors: Louise
authors: L
authors: Pape
authors: James W
authors: JW
authors: Canary
mesh_terms: D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry*; D004587:Electrophoresis, Agar Gel; D006868:Hydrolysis; D007700:Kinetics; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D009596:Nitrophenols / Q000737:chemistry; D010755:Organophosphates / Q000737:chemistry*; D010727:Phosphoric Diester Hydrolases / Q000737:chemistry; D011725:Pyridines / Q000737:chemistry
chemical_list: D008024:Ligands; D009596:Nitrophenols; D010755:Organophosphates; D011725:Pyridines; C431843:tris(2-pyridylmethyl)amine; C002887:bis(4-nitrophenyl)phosphate; D003300:Copper; D004247:DNA; D010727:Phosphoric Diester Hydrolases