Quenching of fluorescence by meclizine, a probe study for structural and conformational changes in human serum albumin

Abstract

The goal of this study was to investigate the interactions between meclizine (MEC) and human serum albumin (HSA) under physiological conditions by different spectroscopies and molecular modeling technique. The drug, MEC quenched the intrinsic fluorescence of HSA and the analysis of the results revealed that static quenching mechanism. The binding of MEC quenches the HSA fluorescence; stoichiometry was 1:1 interaction. Thermodynamic quantities were calculated at different temperatures suggested that hydrophobic and van der Waals interaction with HSA–MEC. The molecular distance, r, between donor and acceptor was estimated according to Forster’s theory of non-radiation energy transfer. CD and FT-IR studies confirm changes of secondary structure of HSA. Molecular docking studies validate MEC molecule interact to HSA in sub domain IIA.

Keywords:

• human serum albumin
• meclizine
• Forster’s energy transfer
• circular dichroism
• molecular docking

Acknowledgements

One of the authors (Girish G. Ariga) thanks Karnatak University, Dharwad, for the Research Fellowship (KU/Sch/UGC–UPE/2013/14/1114) under the UGC–UPE program (2013–16). The authors thank the Chairman, Department of Molecular Biophysics, Indian Institute of Science, Bangalore for CD measurement facilities.

Disclosure statement

No potential conflict of interest was reported by the authors.