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

Eurobic9, 2-6 September, 2008, Wrocław, Poland
P192. A Binding Site of Metal Complexes on Serum Albumin:
Computational Binding Energies and Calorimetric Binding Constants
T. Taura, K. Suyama
Group of Chemistry, Graduate School of Information Science and Technology, University of Aichi Prefecture,
Nagakute, 480-1198 Aichi, Japan
Human serum albumin is the main transport protein in the blood. This protein comprises 60% of the total plasma
protein. Albumin plays an essential role in the transport and delivery of metal ions, fatty acids and other small
molecules or ions [1, 2]. It seems that anionic compounds of these materials strongly bind to the amino acids,
Lys, Arg and His which provide a three dimensional space around cationic side chains in subdomain IIA of the
albumin structure (Site I). Although albumin is thought to be the major transport protein for inorganic and
organic compounds in the blood, precise images of these binding sites are not clear.
Therefore, we tried to detect the sites of albumin to which metal complexes bind by computational simulations.
Binding energies of the metal complex anions to albumins including human, bovine, pig and sheep were
calculated for docking poses after structural optimizations. By contrast, binding constants of these complex
anions with albumins were obtained by the calorimetric measurement. The large values of binding constants
correspond to the large binding energies obtained by the computational methods. Good correlation between
computed binding energies and measured binding constants suggests that the images of binding sites could be
correct.
References:
[1] T. Peters, Jr., All about Albumin, 1996, Academic Press.
[2] D. C. Carter, J. X. Ho, Adv. Protein Chem., 1994, 45, 153-204.
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