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

Eurobic9, 2-6 September, 2008, Wrocław, Poland
SL15. Mass Spectrometry and NMR for Spectroscopically Silent Metal
Ions: Lessons from Zinc Metallothioneins from Bacteria and Plants
C. Blindauer , O. Leszczyszyn
Chemistry, University of Warwick, Gibbet Hill Road, CV4 7AL, Coventry, United Kingdom,
e-mail: c.blindauer@warwick.ac.uk
In contrast to the plethora of spectroscopic techniques that are available to study iron-binding proteins, methods
for directly observing the metal ion binding properties of zinc-binding proteins, such as coordination mode,
uptake and release are far more limited. Recent advances in mass spectrometry instrumentation allow
observation of native metalloproteins including, in favourable cases, following metal binding events in real time,
as shown in the Figure. Such experiments are aided by the fact that biologically relevant zinc complexes are
often relatively stable. Similarly, for NMR spectroscopy, the diamagnetic nature of Zn(II) is advantageous,
allowing the application of a variety of multinuclear NMR techniques. Discussing our recent work concerning
bacterial metallothioneins from various cyanobacteria [1, 2], as well as the plant metallothionein wheat EC [3],
we will demonstrate that the combination of these two experimental techniques, together with site-directed
mutagenesis and molecular modelling, is a powerful approach to understand metal ion binding thermodynamics
and kinetics in great detail.
Acknowledgement: We thank the Royal Society (Olga Kennard Fellowship to C.A.B.), the EPSRC, the
BBSRC, the Wellcome Trust, and the European Commission for support.
References:
[1] C. A. Blindauer, M. T. Razi, D. J. Campopiano, P. J. Sadler, J. Biol. Inorg. Chem. 2007, 12, 393-405.
[2] O. I. Leszczyszyn, C. D. Evans, S. E. Keiper, G. Z. L. Warren , C. A. Blindauer, Inorg. Chim. Acta 2007,
360, 3-13.
[3] O. I. Leszczyszyn, R. Schmid, C. A. Blindauer, Proteins 2007, 68, 922-935.
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