Multi-spectroscopic investigation of the binding interaction of fosfomycin with bovine serum albumin

Abstract

The interaction between fosfomycin (FOS) and bovine serum albumin (BSA) has been investigated effectively by multi-spectroscopic techniques under physiological pH 7.4. FOS quenched the intrinsic fluorescence of BSA via static quenching. The number of binding sites n and observed binding constant KA were measured by the fluorescence quenching method. The thermodynamic parameters ΔG0, ΔH0 and ΔS0 were calculated at different temperatures according to the van’t Hoff equation. The site of binding of FOS in the protein was proposed to be Sudlow’s site I based on displacement experiments using site markers viz. warfarin, ibuprofen and digitoxin. The distance r between the donor (BSA) and acceptor (FOS) molecules was obtained according to the Förster theory. The effect of FOS on the conformation of BSA was analyzed using synchronous fluorescence spectra (SFS), circular dichroism (CD) and 3D fluorescence spectra. A molecular modeling study further confirmed the binding mode obtained by the experimental studies.

Interaction of a Triaryl Methane Dye with Cucurbit[7]uril and Bovine Serum Albumin: A Perspective of Cooperative versus Competitive Bindings

“…In CV‐BSA system, the CV molecules are expected to get entrapped more preferentially into the Sudlow's Site I of BSA, as we discussed earlier. Since this binding site contains a tryptophan residue (Trp‐212), we expect that binding of CV into this pocket would lead to some interaction of the bound dye with the Trp‐212 residue of BSA, which can suitably be realized by monitoring the intrinsic fluoresce of BSA. In the SS fluorescence measurements, however, we could not obtain any conclusive information from such a study because the 280 nm absorption band of BSA is strongly overlapped with the higher energy absorption band of CV such that the selective excitation of BSA was not possible.…”

“…Bovine serum albumin (BSA; cf . Figure B), which is a transport protein and resembles structurally very closely to human serum albumin (HSA), has been used widely as a model to investigate various drug‐protein interactions . In the pH range of 5–7, the heart shaped structural motif of BSA contains three homologous α‐helical domains I, II and III, each of them are again divided into two sub‐domains A and B, respectively.…”

“…Due to its non‐planar and flexible structure, the excited state of CV undergoes very fast non‐radiative deexcitation process and hence the free dye is extremely weak in fluorescence . Upon binding to a macrocyclic cavity or to a biomacromolecular pocket, the dye, however, can display large enhancement in fluorescence intensity, due to large reduction in the non‐radiative deexcitation processes, caused by the imposed restriction on the flexibility of the dye molecules due to the confinement effect , In the literature CV has been emphasized as a useful dye for staining various bio‐organisms, having antifungal, antibacterial, anthelmintic and antiparasitic properties and being effective in photodynamic therapy ,…”

Interaction studies of copper complex containing food additive carmoisine dye with human serum albumin (HSA): Spectroscopic investigations

“…Far‐UV CD spectra measurements have been broadly used for biological chemistry and structural biology especially for secondary structure determination of proteins and polypeptides in solution …”

Effect of Ampicillin and Chloramphenicol on Chick Serum

“…Bovine serum albumin (BSA) is a transport protein found in serum which plays a major role in regulating the circulatory system in the human body [1]. It is a globular protein with 583 amino acids [2].…”