Site-Selective Interaction of Human Serum Albumin with 4-Chloro-7-nitro-1,2,3-benzoxadiazole Modified Olanzapine Derivative and Effect of β-Cyclodextrin on Binding: In the Light of Spectroscopy and Molecular Docking

Abstract

Here, we present a detailed investigation on the interaction of 4-chloro-7-nitro-1,2,3-benzoxadiazole (NBD) embedded olanzapine derivative (OLA-NBD) with a model transport protein, human serum albumin (HSA). The thermodynamic parameters, ΔH o , ΔS o , and ΔG o , as evaluated by considering the van't Hoff relationship imply the major contribution of electrostatic/ionic interactions for the HSA−OLA-NBD association. The OLA-NBD induced quenching of HSA emission occurs through static quenching mechanism, indicating a 1:1 association, as portrayed from Benesi−Hildebrand plot, with ∼10 4 M −1 association constant value, and it is in good harmony with the value estimated from anisotropy experiment. The invariance of the time-resolved decay behavior of HSA with added OLA-NBD concentration, along with matching dependency of the binding constant (K b ) value on temperature, also supports the occurrence of static quenching. The effect of β-cyclodextrin on HSA−OLA-NBD binding is characterized by a smaller K b value revealing that the OLA-NBD molecules are gradually removed from β-CD by HSA to achieve its medicinal outcome of drug delivery. The outcome from circular dichroism (CD) illustrates the variation of HSA secondary structure upon interaction with OLA-NBD. Concurrently, HSA−OLA-NBD association kinetics is also explored by applying the fluorescence technique. The possible interaction zone of OLA-NBD in HSA is investigated from AutoDock-based docking simulation study.

Specific chiroptical sensing of cysteine via ultrasound-assisted formation of disulfide bonds in aqueous solution

“…For N-arylation derivatization of common amino acids, excess NBD analogues and harsh conditions, such as prolonged stirring with heating, are needed to achieve a high yield [52] , [53] , [54] , [55] . However, for Cys, the thiol group is more nucleophilic than amino group.…”

“…2 b). In contrast to harsh conditions for 1 to derive amino acids other than Cys [52] , [53] , [54] , [55] , the optimized reaction conditions were mild.…”

Modulation of the Protein–Ligand Interaction in the Presence of Graphene Oxide: a Detailed Spectroscopic Study

“…These can be substantiated later from the time-resolved fluorescence measurements. The blueshifting of the emission maxima attributed to the lowering of the medium’s polarity surrounding the dye-binding site within the protein. , The continuous increment of fluorescence intensity of 7-DCA in HSA is attributed to the reduction of nonradiative decay channels by TICT state formation, which is generally highly stabilized in the bulk aqueous buffer phase. Now, it is essential to explain the effect of GO on the binding of 7-DCA with HSA.…”

Insight into Molecular Interactions of Two Methyl Benzoate Derivatives with Bovine Serum Albumin

“…Serum albumins, the most abundant proteins in the blood plasma, play a significant role in the transport of both exogenous and endogenous compounds. Several experimental and theoretical studies have shown that human serum albumin (HSA) and bovine serum albumin (BSA) present an ideal model of serum carrier protein, and therefore they are most widely used as model proteins in evaluating small organic molecules (drug)−protein interactions [ 15 , 20 , 21 , 22 , 23 ]. BSA finds a wider range of applications because of its (i) low cost, (ii) high water solubility (iii) almost 80% sequence homology with HSA and (iv) widespread availability in a pure form.…”