Enantioselective Human Serum Albumin Binding of Apremilast: Liquid Chromatographic, Fluorescence and Molecular Docking Study

Abstract

The interaction between human serum albumin (HSA) and apremilast (APR), a novel antipsoriatic drug, was characterized by multimodal analytical techniques including high-performance liquid chromatography (HPLC), fluorescence spectroscopy and molecular docking for the first time. Using an HSA chiral stationary phase, the APR enantiomers were well separated, indicating enantioselective binding between the protein and the analytes. The influence of chromatographic parameters—type and concentration of the organic modifier, buffer type, pH, ionic strength of the mobile phase, flow rate and column temperature—on the chromatographic responses (retention factor and selectivity) was analyzed in detail. The results revealed that the eutomer S-APR bound to the protein to a greater extent than the antipode. The classical van ’t Hoff method was applied for thermodynamic analysis, which indicated that the enantioseparation was enthalpy-controlled. The stability constants of the protein–enantiomer complexes, determined by fluorescence spectroscopy, were in accordance with the elution order observed in HPLC (KR-APR-HSA = 6.45 × 103 M−1, KS-APR-HSA = 1.04 × 104 M−1), showing that, indeed, the later-eluting S-APR displayed a stronger binding with HSA. Molecular docking was applied to study and analyze the interactions between HSA and the APR enantiomers at the atomic level. It was revealed that the most favored APR binding occurred at the border between domains I and II of HSA, and secondary interactions were responsible for the different binding strengths of the enantiomers.

Impact of Sinapic Acid on Bovine Serum Albumin Thermal Stability

“…Moreover, recent results pointed to thermal denaturation and aggregation as a threat to global distribution of biologics and research-use-only (RUO) proteins in a relatively high temperature environment [18]. Calorimetric [19], spectroscopic [20], and molecular docking [21,22] approaches are extensively used to study and analyze the interaction of different ligands with proteins and their applications in various research domains.…”

Enantioselective binding of carvedilol to human serum albumin and alpha‐1‐acid glycoprotein

“…20,21 These methods are based on the physical separation of the free and protein-bound fractions of a drug, with the difference that in the case of UC, the separation is achieved solely by the centrifugal force applied, whereas ED and UF rely on the use of a semipermeable membrane. Furthermore, some studies suggest the use of chiral HSA and AGP columns as a simple and rapid method to characterize and prove enantioselective binding 22 ; however, this method also has its limitations, and, in other studies, it has been reported to not always give suitable results considering the class of the β-blocking agents. 23 For the present study, considering the advantages and limitations of each method, UF was chosen as being most suitable.…”

Chiral Separation of Apremilast by Capillary Electrophoresis Using Succinyl-β-Cyclodextrin—Reversal of Enantiomer Elution Order by Cationic Capillary Coating

“…For this drug, the more potent S-enantiomer is marketed; therefore, the determination of the R-antipode is a requirement [7,8]. Although several chromatographic methods are described or at least mentioned for the achiral [9,10] and chiral separation of apremilast [11][12][13][14][15][16], based on the authors' knowledge, enantioseparation of APR with capillary electrophoresis was not yet described. marketed; therefore, the determination of the R-antipode is a requirement [7,8].…”

“…marketed; therefore, the determination of the R-antipode is a requirement [7,8]. Although several chromatographic methods are described or at least mentioned for the achiral [9,10] and chiral separation of apremilast [11][12][13][14][15][16], based on the authors' knowledge, enantioseparation of APR with capillary electrophoresis was not yet described. Although LC is the most common choice for enantioseparations, alternative techniques such as capillary electrophoresis (CE) present several advantages over LC.…”