title: A structural and catalytic model for zinc phosphoesterases.
abstract: A structural model for the active site of phosphoesterases, enzymes that degrade organophosphate neurotoxins, has been synthesised. The ligand [2-((2-hydroxy-3-(((2-hydroxyethyl)(pyridin-2-ylmethyl)amino)methyl)-5-methylbenzyl)(pyridin-2-ylmethyl)amino)acetic acid] (H(3)L1) and two Zn(ii) complexes have been prepared and characterised as [Zn(2)(HL1)(CH(3)COO)](PF(6)).H(2)O and Li[Zn(2)(HL1)](4)(PO(4))(2)(PF(6))(3).(CH(3)OH). The ligand (H(3)L1) and complex [Zn(2)(HL1)(CH(3)COO)](PF(6)).H(2)O were characterised through (1)H NMR, (13)C NMR, mass spectroscopy and microanalysis. The X-ray crystal structure of Li[Zn(2)(HL1)](4)(PO(4))(2)(PF(6))(3).(CH(3)OH) revealed a tetramer of dinuclear complexes, bridged by two phosphate molecules and bifurcating acetic acid arms. Functional studies of the zinc complex with the substrate bis(4-nitrophenyl)phosphate (bNPP) determined the complex with HL1(2-) to be a competent catalyst with k(cat) = 1.26 +/- 0.06 x 10(-6) s(-1).
authors.affiliation: School of Molecular and Microbial Sciences, The University of Queensland, Queensland, Australia 4072.
authors.forename: Rebecca R
authors.initials: RR
authors.lastname: Buchholz
authors.forename: Morgan E
authors.initials: ME
authors.lastname: Etienne
authors.forename: Anneke
authors.initials: A
authors.lastname: Dorgelo
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Mirams
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Smith
authors.forename: Shiao Yun
authors.initials: SY
authors.lastname: Chow
authors.forename: Lyall R
authors.initials: LR
authors.lastname: Hanton
authors.forename: Geoffrey B
authors.initials: GB
authors.lastname: Jameson
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schenk
authors.forename: Lawrence R
authors.initials: LR
authors.lastname: Gahan
mesh_terms: D055162:Biocatalysis; D018360:Crystallography, X-Ray; D004950:Esterases / Q000737:chemistry* / Q000378:metabolism*; D006860:Hydrogen Bonding; D013058:Mass Spectrometry; D008958:Models, Molecular; D010710:Phosphates / Q000378:metabolism*; D015032:Zinc / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D010710:Phosphates; D004950:Esterases; D015032:Zinc