Mechanistic Interaction Study of Bromo-Noscapine with Bovine Serum Albumin employing Spectroscopic and Chemoinformatics Approaches

Bromo-Noscapine (BrNs) is a tubulin-binding cytotoxic agent with significant activity against breast and lung cancer. The mechanistic interaction insight into the binding of bovine serum albumin (BSA) with BrNs can provide critical information about the pharmacodynamics and pharmacokinetics properties. Here, various spectroscopic techniques and computational methods were employed to understand the dynamics of BrNs and BSA interaction. The intrinsic fluorescence of BSA was quenched by BrNs through a static quenching procedure. The stoichiometry of BrNs-BSA complex was 1:1 and binding constant of the complex was in the order of 10³ M^-1 at 298 K. Based on thermodynamic analysis, it was deduced that binding process of the BrNs with BSA was spontaneous and exothermic, and the major forces between BrNs and BSA were van der waals forces and hydrogen bonding. Moreover, results of FT-IR, CD, UV spectra concluded significant conformational change in BSA on binding with BrNs. The in vitro findings were further confirmed by in silico assays. Molecular docking showed strong interactions with score of -8.08 kcal/mol. Molecular dynamics simulation analysis also suggested the stable binding with lower deviation in RMSD and RMSF values through persistent long simulation run. This study suggests optimal efficiency of diffusion of the BrNs into the bloodstream for the treatment of cancer.