Investigation of the interaction between bromocriptine and human serum albumin with spectroscopic techniques and computational approaches

Ozsar S. A., Kanbes-Dindar C., Rehman F., Mohamad S. B., USLU B.

Journal of Biomolecular Structure and Dynamics, cilt.44, sa.7, ss.3319-3336, 2026 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 44 Sayı: 7
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1080/07391102.2025.2513017
  • Dergi Adı: Journal of Biomolecular Structure and Dynamics
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, CAB Abstracts, Chemical Abstracts Core
  • Sayfa Sayıları: ss.3319-3336
  • Anahtar Kelimeler: Bromocriptine, drug–protein interaction, fluorescence, human serum albumin, molecular docking
  • Ankara Üniversitesi Adresli: Evet

Özet

Fluorescence and absorption spectroscopy coupled with molecular docking techniques were chosen to reveal the molecular relationship between bromocriptine (BRC), a dopamine agonist, and human serum albumin (HSA), the major carrier protein in the bloodstream. The gradual decrease of Stern-Volmer constant (KSV) with increasing temperatures noted that BRC induced quenching in HSA fluorescence occurred via a static quenching mechanism, thus indicating the formation of complexes between BRC and HSA. The changes observed in the UV-vis absorption spectra of HSA as a result of BRC addition and the fact that the biomolecular quenching rate constants (Kq) calculated for the BRC-HSA interaction are significantly larger than the highest value of the dynamic quenching rate constant also support this conclusion. Considering the experimentally obtained binding constant (Ka) values ​​(2.6 − 3.8 x 104 M−1), BRC appeared to bind to HSA with a moderate affinity. Analysis of thermodynamic data suggested the association of hydrophobic interactions, H-bonds and van der Waals forces as the main interaction forces in the BRC–HSA binding. It was determined by 3-D fluorescence spectra that the binding of BRC to the protein led to significant changes in the Tyr/Trp microenvironment of the protein. Docking analyses and drug displacement experiments identified that BRC likely binds to subdomain IIA (Site I) of HSA.