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

Eurobic9, 2-6 September, 2008, Wrocław, Poland
P53. Biomimetic Models for Fe/S Clusters Involved in Radical Reactions
M.G.G. Fuchs a , S. Dechert a , U. Ryde b , F. Meyer a
a
Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraße 4, D-37077
Göttingen, German
e-mail: michael.fuchs@chemie.uni-goettingen.de
b
Department of Theoretical Chemistry, Lund University, Chemical Center, S-22100 Lund, Sweden
Fe/S clusters are discussed as the sulphur sources in biochemical radical reactions in which S atoms are inserted
into substrates. A [4Fe–4S] cluster is the probable sulphur source in the reactions catalysed by lipoyl synthase
(LipA) [1] and tRNA-methylthiotransferase (MiaB)[2] whereas in biotin synthase (BioB), a [2Fe–2S] cluster
delivers the S atom for insertion into the substrate dethiobiotin. [3] This [2Fe–2S] cluster carries an unusual
arginine ligand which might enhance reactivity by providing additional interactions around one of the Fe atoms.
[4]
Model reactions using biomimetic Fe/S clusters and organic radicals are investigated in order to emulate the
proposed enzyme mechanisms. Furthermore, Fe/S clusters with unusual coordination are synthesised and
characterised [5] to clarify the role of the unprecedented arginine ligand of the biotin synthase Fe/S cluster.
Acknowledgement: Financial support from Fonds der Chemischen Industrie (Kekulé fellowship for M. G. G.
F.) and Deutsche Forschungsgemeinschaft (IRTG 1422) is gratefully acknowledged.
References:
[1] J. R. Miller, R. W. Busby, S. W. Jordan, J. Cheek, T. F. Henshaw, G. W. Ashley, J. B. Broderick, J. E.
Cronan Jr., M. E. Marletta, Biochemistry, 39, 15166 (2000).
[2] H. L. Hernández, F. Pierrel, E. Elleingand, R. García-Serres, B. H. Huynh, M. K. Johnson, M. Fontecave, M.
Atta, Biochemistry, 46, 5140 (2007).
[3] N. B. Ugulava, C. J. Sacanell, J. T. Jarrett, Biochemistry, 40, 8352 (2001).
[4] F. Berkovitch, Y. Nicolet, J. T. Wan, J. T. Jarrett, C. L. Drennan, Science, 303, 76 (2004).
[5] J. Ballmann, S. Dechert, E. Bill, U. Ryde, F. Meyer, Inorg. Chem., 47, 1586 (2008).
M. G. G. Fuchs, S. Dechert, U. Ryde, F. Meyer, unpublished results.
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