ISBN: 978-83-60043-10-3 - eurobic9

Eurobic9, 2-6 September, 2008, Wrocław, Poland
P85. Homo- and Heterodinuclear Metal Complexes of Symmetric and
Asymmetric Ligands for Modeling of Active Sites in Metallohydrolases
M. Jarenmark, a M. Haukka b and E. Nordlander a
a Inorganic Chemistry Research Group, Department of Chemical Physics, Centre for Chemistry and Chemical
Engineering, Lund University, Box 124, SE-221 00, Sweden
e-mail: martin.jarenmark@chemphys.lu.se
b Department of Chemistry, University of Joensuu, Box 111, FI-80101 Joensuu, Finland
Several hydrolytic enzymes containing dinuclear active sites catalyse the cleavage of phosphoester bonds with
high efficiency. Prominent examples are zinc phosphotriesterase that contain two hydroxido bridged Zn(II) ions
and purple acid phosphatases that contain a Fe(III) and a divalent metal ion (Fe, Zn or Mn) bridged by a
hydroxido or oxido group in the active site.
To model these sites several dinuclear metal complexes have been synthesized using the ligands IPCPMP and
BCPMP.[1] Zinc complexes with these ligands catalyse the transesterfication of 2-hydroxypropyl-p-nitrophenol
phosphate (HPNP) yielding a considerable higher rate with the asymmetric ligand IPCPMP and a strong pH
dependence. The solid-state structures indicate that a tetranuclear complex may be responsible for the higher
activity.
With IPCPMP a mononuclear Fe(III) complex can be synthesized which can be used to selectively form several
heterodinuclear metal complexes where the structure of the FeZn, FeCo, FeNi and FeCu derivatives have been
determined by X-ray crystallography. The FeZn, FeCo and FeNi complexes also catalyses the transesterfication
of HPNP.
Acknowledgements: The authors would like to thank the Swedish research council, the International research
training group ‘Metal sites in biomolecules: Structures, regulation and mechanisms’ and the faculty of natural
sciences at Lund University for financial support.
References:
[1]M. Jarenmark, S. Kappen, M. Haukka E. Nordlander, Dalton Trans., 2008, 993 - 996
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