Comparison of various capillary electrophoretic approaches for the study of drug–protein interaction with emphasis on minimal consumption of protein sample and possibility of automation†

Abstract

The binding ability of a drug to plasma proteins influences the pharmacokinetics of a drug. As a result, it is a very important issue in new drug development. In this study, affinity capillary electrophoresis, capillary electrophoresis with frontal analysis, and Hummel Dreyer methods with internal and external calibration were used to study the affinity between bovine serum albumin and salicylic acid. The binding constant was measured by all these approaches including the equilibrium dialysis, which is considered to be a reference method. The comparison of results and other considerations showed the best electrophoretic approach to be capillary electrophoresis-frontal analysis, which is characterized by the high sample throughput with the possibility of automation, very small quantities of biomacromolecules, simplicity, and a short analysis time. The mechanism of complex formation was then examined by capillary electrophoresis with frontal analysis. The binding parameters were determined and the corresponding thermodynamic parameters such as Gibbs free energy ΔG(0), enthalpy ΔH(0), and entropy changes ΔS(0) at various temperatures were calculated. The results showed that the binding of bovine serum albumin and salicylic acid was spontaneous, and that hydrogen bonding and van der Waals forces played a major role in the formation of the complex.

Study on the interactions of sulfonylurea antidiabetic drugs with normal and glycated human serum albumin by capillary electrophoresis‐frontal analysis

“…Many methods have been developed for studying drug–protein interactions including CE with its several important benefits in this field, such as no need for (i) highly purified samples, (ii) immobilization, and (iii) labelling of any of the interacting species . Recently we performed a comprehensive evaluation of the three most used CE approaches for the study of drug–protein interaction, ACE, capillary electrophoresis‐frontal analysis (FA) and Hummel Dreyer methods with internal and external calibrations using HSA–salicylic acid as a model affinity pair . The comparison indicated CE–FA to be the best approach, characterized by a high sample throughput with the possibility of automation, very small quantities of biomacromolecules, simplicity and a short analysis time.…”

In‐depth insight into the methods of plasma protein‐drug interaction studies: Comparison of capillary electrophoresis‐frontal analysis, isothermal titration calorimetry, circular dichroism and equilibrium dialysis

“…They are characterized by several important benefits such as no need for highly purified samples, immobilization, and labelling of any of the interacting partners. Recently Michalcová et al performed a systematic evaluation of the three most used CE approaches for the study of plasma protein-drug interaction -affinity capillary electrophoresis, CE-FA and the Hummel-Dreyer method -using BSA-salicylic acid as the model system [21]. Their comparison, focused mainly on a capacity for high sample throughput with the possibility of automation and minimal consumption of samples, showed CE-FA to be the best approach.…”

Recent developments in capillary and microchip electroseparations of peptides (2013–middle 2015)

“…In ACE, a high selectivity of (bio)affinity recognition is combined with high separation efficiency of CE in a free solution. Thus, ACE possesses a great potential for investigation of the (bio)molecular noncovalent interactions under mild conditions and for estimation of binding (stability, association, formation) or dissociation constants of the formed complexes as demonstrated in several recent reviews . ACE involves several modes based either on the separation of the interacting species and determination of their equilibrium concentration, such as in the Hummel–Dreyer method , the vacancy peak method , frontal analysis , continuous frontal analysis , and kinetic CE , or on the detection of a specific physicochemical property of the complexed ligand or the binding partner, mostly the mobility shift assay .…”

“…All these methods utilize the differences in the migration velocities of the interacting species. Both theoretical and experimental considerations for these methods and their applications for estimation of binding constants have been outlined in the above reviews [] ; the particular recent applications to peptide interaction studies are presented in the Section .…”