Determination of modes of interactions of lanosterol with bovine serum albumin (BSA) using different spectroscopic techniques and molecular docking

Abstract

Abstract Graphical abstract Abstract Lanosterol is a natural steroidal molecule which is used as an anti-cataract agent. In the present work, binding interactions of lanosterol with bovine serum albumin (BSA) were determined with different spectroscopic techniques, including UV-spectrophotometry, fluorimetry, circular dichroism spectroscopy, nanoDSF, and molecular docking. UV absorption spectroscopy showed the formation of a ground-state complex between lanosterol and bovine serum albumin (BSA). Fluorimetric analysis showed that lanosterol quenched the intrinsic fluorescence of BSA through a static quenching mechanism with a binding constant of 6.19×107 M-1 at 297 K. Thermodynamic parameters showed that the reaction was spontaneous, and the main interacting forces of this complex were found to be hydrophobic. Circular dichroism showed stable changes in the secondary structural contents of BSA while binding with lanosterol. This indicated the conformational changes in the structure of the protein during the binding of this compound. NanoDSF studies showed an increase in protein stability in the presence of 9.75 µM to 78 µM concentration of lanosterol. Docking studies showed the binding of lanosterol in site I through hydrophobic interactions. Since no information is available so far regarding binding studies between lanosterol and BSA, this study may provide initial insights about lanosterol-BSA interactions that can be used for further to investigate pharmacological properties.