Determination of binding constants and stoichiometries for platinum anticancer drugs and serum transport proteins by capillary electrophoresis using the Hummel-Dreyer method

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

A CE method has been developed to evidence and quantitatively characterize the interaction between platinum-based antitumor drugs and human serum proteins. This method is a variant of affinity CE modified regarding both experimental setup and data treatment so as to measure the peaks (or vacancies) that correspond to the bound drug when it slowly binds to the protein. Using the formalism of the Hummel-Dreyer method and cisplatin and oxaliplatin as test compounds, a protocol for determining albumin and transferrin binding constants and stoichiometries, including (and distinguished by) 48 hours of incubation of the reaction mixture, was elaborated. Relative affinities of drugs toward different proteins in aqueous solution at physiological pH, chloride concentration, and temperature were compared in terms of overall binding constants and numbers of drug molecules attached to the protein. The results indicate that both platinum drugs bind to albumin more strongly than to transferrin, supporting the concept that the albumin fraction is a major drug supply route for chemotherapeutical needs. From a comparison with the binding parameters measured previously for cisplatin by other methods, conclusions were drawn about the validity of CE as a simple and convenient method for assaying protein-drug reactions with slow kinetics. Œ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Organisation(s)
Department of Inorganic Chemistry
External organisation(s)
Russian Academy of Sciences, Saratov Institute of Radiation, Chemical and Biological Warfare Defense
Journal
Journal of Separation Science
Volume
28
Pages
121-127
No. of pages
7
ISSN
1615-9306
Publication date
2005
Peer reviewed
Yes
Austrian Fields of Science 2012
1040 Chemistry
Portal url
https://ucrisportal.univie.ac.at/en/publications/4f264525-b219-4ff1-9865-324d5cfad10f