Comparative binding of antitumor indazolium [trans-tetrachlorobis(1H- indazole)ruthenate(III)] to serum transport proteins assayed by capillary zone electrophoresis

Author(s)
Andrei Timerbaev, Alexander V. Rudnev, Olga Semenova, Christian Hartinger, Bernhard Keppler
Abstract

The indazolium [trans-tetrachlorobis(1H-indazole)ruthenate(III)] coordination compound shows notable antiproliferative activity in different tumor models and has recently ended phase I clinical trials as a lead anticancer metallodrug candidate. Its approval could be greatly facilitated if more precise information was available on the rate and degree of the drug's transformation occurring upon interaction with serum transport proteins and on the stability of the adducts formed. With this objective, a new method has been developed for the determination of the protein-binding rate and association constants under simulated physiological conditions by capillary zone electrophoresis (CZE). These binding parameters were assessed by monitoring the time- and concentration-dependent changes in peak area responses of reaction components, constructing the corresponding binding curves, and conducting a mathematical analysis. Comparison of the apparent rate constants determined by CZE revealed that indazolium [trans-tetrachlorobis(1H-indazole)ruthenate(III)] binds to transferrin much faster than to albumin: k = 39.5 × 10-4 and 3.3 × 10-4 s-1, respectively. The corresponding association constants are indicative of moderate metal-protein coordination, with a somewhat higher affinity of the Ru complex toward albumin (9910 and 6460 M-1, respectively). The results of our study confirm in a quantitative manner that, in real bloodstream circumstances, plasma albumin may serve as a reservoir and a natural carrier of the administered ruthenium drug and hence mediate its accumulation in tumors. © 2005 Elsevier Inc. All rights reserved.

Organisation(s)
Department of Inorganic Chemistry
External organisation(s)
Russian Academy of Sciences
Journal
Analytical Biochemistry
Volume
341
Pages
326-333
No. of pages
8
ISSN
0003-2697
DOI
https://doi.org/10.1016/j.ab.2005.03.020
Publication date
2005
Peer reviewed
Yes
Austrian Fields of Science 2012
104002 Analytical chemistry, 106002 Biochemistry, 301904 Cancer research
Sustainable Development Goals
SDG 3 - Good Health and Well-being
Portal url
https://ucrisportal.univie.ac.at/en/publications/93c22b54-dd9a-418d-8b55-cbe0b03dbc47