Insight into the interaction of isochroman with bovine serum albumin: extensive experimental and computational investigations

Abstract

The way therapeutic compounds interact with serum protein provides valuable information on their pharmacokinetics, toxicity, effectiveness, and even their structural-related information. Isochroman (IC) is a phytochemical compound obtained from the leaves of Olea europea plant. The derivatives of IC have various pharmacological properties including antidepressants, antihistamines, antiinflammation, anticonvulsants, appetite depressants, etc. The binding of small molecules to bovine serum albumin (BSA) is useful to ensure their efficacy. Thus, in this study, we have found out the binding mode of IC with BSA using several spectroscopic and in silico studies. UV and fluorescence spectroscopy suggested the complex formation between IC and BSA with a binding constant of 10³ M⁻¹. IC resulted in fluorescence quenching in BSA through static mechanism. The microenvironmental and conformational changes in BSA were confirmed using synchronous and three-dimensional studies. Site marker experiment revealed the IC binding in site-III of BSA. The influence of vitamins, metals and β-cyclodextrin (β-CD) on binding constant of IC–BSA complex was also examined. Circular dichroism spectra showed that α-helical of BSA decreased upon interaction with IC. Computational and experimental results were complimentary with one another and assisted in determining the binding sites, nature of bonds and amino acids included in the IC–BSA complex formation.

Communicated by Ramaswamy H. Sarma

Keywords:

• Bovine serum albumin
• isochroman
• spectroscopy
• β-cyclodextrin
• computational modelling

Acknowledgements

The authors gratefully acknowledge DBT for providing JRF to S.F., ICMR for providing SRF to I.H., UGC Non-NET for providing to S.A. and CSIR for providing SRF to M.A.A. We also appreciate the significant funding provided to the Department of Biochemistry, Faculty of Life Sciences, by the UGC-DRS-SAP and DST-FIST. The authors also thank the Department of Biochemistry (Aligarh Muslim University) for providing the necessary experimental facilities.

Author contributions

S.F.: conceptualisation, roles/writing – original draft, data curation, methodology, formal analysis and validation. I.H.: conceptualisation, software analysis, data curation and writing – review and editing. S.A. and M.A.A.: software analysis and writing – review and editing. M.T.: supervision.

Disclosure statement

The authors report that there is no conflict of interest.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.