Domain-Specific Association of a Phenanthrene–Pyrene-Based Synthetic Fluorescent Probe with Bovine Serum Albumin: Spectroscopic and Molecular Docking Analysis

Abstract

In this report, the interaction between a phenanthrene–pyrene-based fluorescent probe (PPI) and bovine serum albumin (BSA), a transport protein, has been explored by steady-state emission spectroscopy, fluorescence anisotropy, far-ultraviolet circular dichroism (CD), time-resolved spectral measurements, and molecular docking simulation study. The blue shift along with emission enhancement indicates the interaction between PPI and BSA. The binding of the probe causes quenching of BSA fluorescence through both static and dynamic quenching mechanisms, revealing a 1:1 interaction, as delineated from Benesi–Hildebrand plot, with a binding constant of ∼10 5 M –1 , which is in excellent agreement with the binding constant extracted from fluorescence anisotropy measurements. The thermodynamic parameters, Δ H °, Δ S °, and Δ G °, as determined from van’t Hoff relationship indicate the predominance of van der Waals/extensive hydrogen-bonding interactions for the binding phenomenon. The molecular docking and site-selective binding studies reveal the predominant binding of PPI in subdomain IIA of BSA. From the fluorescence resonance energy transfer study, the average distance between tryptophan 213 of the BSA donor and the PPI acceptor is found to be 3.04 nm. CD study demonstrates the reduction of α-helical content of BSA protein on binding with PPI, clearly indicating the change of conformation of BSA.

Spectroscopic and Molecular Docking Study of the Interaction between Neutral Re(I) Tetrazolate Complexes and Bovine Serum Albumin

“…The n values for both 1 and 2 are approximately equal to 1, suggesting that BSA has one binding site for each Re(I) complex. To further support 1 : 1 binding, we also generated a plot based on Benesi‐Hildebrand Equation (S1), the linearity of which indicates 1 : 1 complexation (Figure S7) [43] . The strength of the binding can be deduced from the K b , with higher values indicating stronger binding [44] .…”

Glycoconjugates Based on Supramolecular Tröger’s Base Scaffold: Synthesis, Photophysics, Docking, and BSA Association Study

“…In fact, the H-bonds have an important role in the complex stabilization, as already reported in the literature. 54,55 The interaction of the Tröger’s base in I B 52,56 and II A 51,57,58 subdomains could induce conformational changes in BSA. As a result, the tryptophan fluorescence quenching can be affected.…”

Enhanced and Prolonged Activity of Enzymes Adsorbed on TEMPO-Oxidized Cellulose Nanofibers

“…All measurements were carried out at a scanning speed of 100 nm/min and a loading number of 3. The α-helix, a secondary protein structure, is known to exhibit a negative dichroic peak at 222 nm, and the relative content of α-helices was calculated based on the ellipticity of the obtained CD spectra at 222 nm, as shown in eq 2 ( 27 ) …”