Characterization of the binding sites of the anticancer ruthenium(III) complexes KP1019 and KP1339 on human serum albumin via competition studies

Author(s)
Orsolya Domotor, Christian G. Hartinger, Anna Bytzek, Tamas Kiss, Bernhard Keppler, Eva Anna Enyedy
Abstract

Indazolium trans-[tetrachloridobis(1H-indazole)ruthenate(III)] (KP1019) and its Na+ analogue (KP1339) are two of the most prominent non-platinum antitumor metal complexes currently undergoing clinical trials. After intravenous administration, they are known to bind to human serum albumin (HSA) in a noncovalent manner. To elucidate their HSA binding sites, displacement reactions with the established site markers warfarin and dansylglycine as well as bilirubin were monitored by spectrofluorimetry, ultrafiltration-UV-vis spectrophotometry, and/or capillary zone electrophoresis. Conditional stability constants for the binding of KP1019 and KP1339 to sites I and II of HSA were determined, indicating that both Ru(III) compounds bind to both sites with moderately strong affinity (log K (1)' = 5.3-5.8). No preference for either binding site was found, and similar results were obtained for both metal complexes, demonstrating low influence of the counter ion on the binding event.

Organisation(s)
Department of Inorganic Chemistry
External organisation(s)
University of Szeged, University of Auckland
Journal
Journal of Biological Inorganic Chemistry
Volume
18
Pages
9-17
No. of pages
9
ISSN
0949-8257
DOI
https://doi.org/10.1007/s00775-012-0944-6
Publication date
2013
Peer reviewed
Yes
Austrian Fields of Science 2012
104003 Inorganic chemistry, 104004 Chemical biology
Portal url
https://ucrisportal.univie.ac.at/en/publications/7b96b249-7160-413f-ac47-30dda1bc5145