Wojciech Rogóż, Julia Szczypta, Małgorzata Maciążek-Jurczyk

Study of streptomycin and ibuprofen binding to HSA and their effect on the protein’s antioxidant activity

 

2024-12-02

Object of study. A common feature of many diseases is inflammation and oxidation-reduction imbalance. For this reason, antibiotic therapy with the use of nonsteroidal anti-inflammatory drugs is a popular choice in the comprehensive treatment of bacterial diseases and infections. Based on the available sources, it was determined that there is not a lot of information about the effects of ibuprofen (IBU) and streptomycin (STR) on the antioxidant activity and structure of human serum albumin (HSA).

Aim of the study. The aim of this study was to investigate the binding of streptomycin (STR) and ibuprofen (IBU) with human serum albumin (HSA), as well as to evaluate the ability of both drugs to modulate HSA antioxidant activity of HSA.

Materials and methods. Circular dichroism (CD) spectroscopy, isothermal titration calorimetry (nanoITC), and UV-VIS spectroscopy techniques were used to achieve the purpose of this study.

Results. To study the antioxidant activity of HSA, IBU, STR and ligand-protein complexes, DPPH and ABTS colorimetric assays were used. HSA was shown to have high antioxidant potential, while STR and IBU showed very weak potential. The formation of HSA complex with STR led to an increase in the protein antioxidant potential. Measurements using CD in the far ultraviolet range showed that the predominant secondary structure of HSA is -helix, and that binding of HSA with IBU results in a slight increase in its percentage. In addition, both IBU and STR influenced changes in the tertiary structure of HSA. IBU binding induced structural changes in regions of HSA rich in phenylalanine, tyrosines and tryptophan residues, while STR binding caused changes in the sites of tyrosines and tryptophan residues. The results of measurements using UV-VIS spectrophotometry, based on which the second derivative differential spectra of HSA and mixtures of HSA with IBU and STR were determined, partially overlapped with the results obtained by the CD technique in the near ultraviolet range. Calorimetric measurements showed that unlike IBU, STR binds weakly to HSA. The binding proceeded in a spontaneous manner, and the resulting complex is stabilized mainly by ionic as well as hydrophobic bonds.

Conclusions. The study confirms the effect of STR and IBU on the antioxidant activity of HSA, as well as the effect of the ligands on changes in the protein structure. The analysis carried out can provide a basis for further research and expand the knowledge of the influence of drugs on the HSA properties.

Keywords: antioxidants, HSA, calorimetry, spectroscopy, streptomycin.

© Farm Pol, 2024, 80(7): 441–458