Asymmetric mono- and dinuclear GaIII and ZnII complexes as models for purple acid phosphatases

• Verfasst von: Bosch, Simone [VerfasserIn]
• Verfasst von: Comba, Peter [VerfasserIn]
• Verfasst von: Gahan, Lawrence [VerfasserIn]
• Verfasst von: Schenk, Gerhard [VerfasserIn]
• Titel: Asymmetric mono- and dinuclear GaIII and ZnII complexes as models for purple acid phosphatases
• Verf.angabe: Simone Bosch, Peter Comba, Lawrence R. Gahan, Gerhard Schenk
• Jahr: 2016
• Jahr des Originals: 2015
• Umfang: 13 S.
• Fussnoten: Available online 30 December 2015 ; Gesehen am 18.05.2020
• Titel Quelle: Enthalten in: Journal of inorganic biochemistry
• Ort Quelle: New York, NY [u.a.] : Elsevier, 1979
• Jahr Quelle: 2016
• Band/Heft Quelle: 162(2016), Seite 343-355
• ISSN Quelle: 1873-3344
• DOI: doi:10.1016/j.jinorgbio.2015.12.028
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: Asymmetry
• Sach-SW: Dinucleating ligand
• Sach-SW: Hydrogen bonding
• Sach-SW: Kinetics
• Sach-SW: Phosphatase
• Sach-SW: Reaction mechanism
• K10plus-PPN: 1698446608

Abstract

Derivatives of the known dinucleating ligands HL1 (2,6-bis{[bis(pyridin-2-ylmethyl)amino]methyl}-4-methylphenol) and H2L2 (2-{[bis(pyridin-2-ylmethyl)amino]methyl}-6-{[(2-hydroxybenzyl)(pyridine-2-ylmethyl)amino]methyl}-4-methylphenol) with two pivaloylamido hydrogen bond donor substituents, H3L3 and H3L5, have been prepared. The mono-, homo- and heterodinuclear ZnII and GaIII complexes of these ligands have been prepared and characterized. The solution equilibria are discussed on the basis of extensive NMR spectroscopic, mass spectrometric and pH-dependent UV-vis spectroscopic titrations. The phosphoester hydrolysis activity of the complexes has been studied as a function of pH and substrate concentration and analyzed using Michaelis-Menten kinetics. It emerges that the mixed metal (mixed valent) complex of the ligand with an asymmetric disposition of the hydrogen bonding substituents (H3L3) is a functional model for the mixed valent, dinuclear metallohydrolase purple acid phosphatase. This complex combines the essential structural features of the active site of PAP and is the first heterodinuclear model complex mimicking the essential function of PAPs, i.e. the hydrolysis of phosphomonoesters.