Investigating FA-BLG binding mechanisms through spectroscopic and molecular docking approaches

Three different sizes (15.9 ± 2.1 nm, 26.4 ± 3.2 nm and 39.8 ± 4.0 nm, respectively) of citrate-coated silver nanoparticles (SNPs) have been synthesized and characterized. The interactions of the synthesized SNPs with human serum albumin (HSA) at physiological pH have been systematically studied by UV-vis absorption spectroscopy, fluorescence spectroscopy, synchronous fluorescence spectroscopy, three-dimensional fluorescence spectroscopy and circular dichroism (CD) spectroscopy. The results indicate that the SNPs can bind to HSA with high affinity and quench the intrinsic fluorescence of HSA. The binding constants and quenching rate constants were calculated. The apparent association constants (Kapp ) values are 2.14 × 10(4) M(-1) for 15.9 nm SNP, 1.65 × 10(4) M(-1) for 26.4 nm SNP and 1.37 × 10(4) M(-1) for 39.8 nm SNP, respectively. The values of binding constant obtained from the fluorescence quenching data match well with that determined from the absorption spectral changes. These results suggest that the smaller SNPs have stronger interactions to HSA than the larger ones at the same concentrations. Synchronous fluorescence, three-dimensional fluorescence and CD spectroscopy studies show that the synthesized SNPs can induce slight conformational changes in HSA.

Mechanistic insight into the binding of graphene oxide with human serum albumin: Multispectroscopic and molecular docking approach

The interactions between myriocin (ISP-1) and human serum albumin (HSA) were studied by fluorescence spectroscopy, synchronous fluorescence spectroscopy, three-dimensional fluorescence spectroscopy and molecular docking approach. The intrinsic fluorescence of HSA was quenched through a combination of static and dynamic quenching. The binding constants and the number of binding sites were evaluated according to the Stern–Volmer equation. ISP-1 could not bind efficiently to HSA at higher temperatures. The electrostatic force, hydrogen bonding and hydrophobic force were dominant for the binding ISP-1 and HSA. The site I was the primary binding site for the binding ISP-1 and HSA. What’s more, the conformational and microenvironmental changes of HSA during the binding process were studied by synchronous fluorescence spectroscopy and three-dimensional fluorescence spectroscopy. Lys-195, Arg-218, Arg-222 and Val-293 were the important amino acid residues involved in the binding process.

Comparison of synchronous and laser-induced fluorescence spectroscopy applied to the Eu(III)-fulvate complexation

The interaction between resveratrol and catalase was studied by multispectral method and molecular docking simulation

Exploring the binding characteristics of bovine serum albumin with CDK4/6 inhibitors Ribociclib: Multi-spectral analysis and molecular simulation studies

To understand the effect of 17α-ethinylestradiol (EE2) on the conformation changes of bovine serum albumin (BSA), the binding mechanisms of EE2 with BSA were investigated by fluorescence spectroscopy, time-resolved fluorescence spectroscopy, synchronous fluorescence spectroscopy, three-dimensional fluorescence spectroscopy, UV–visible spectroscopy, circular dichroism (CD) spectroscopy and molecular docking. The quenching constants, binding constants, the number of binding sites, thermodynamic parameters, binding distance and the secondary structure changes of BSA were determined. The results of fluorescence quenching experiment suggested that the fluorescence quenching of BSA by EE was due to the formation of complex through static quenching, which was also confirmed by time-resolved fluorescence measurements. The thermodynamic parameters indicated that the binding of EE2 to BSA was driven mainly by van der Waals forces and hydrogen bonding. The conformation alterations of BSA upon EE2 binding were studied by UV–vis spectroscopy and CD spectroscopy. The results of site marker competitive experiments and molecular docking showed that the binding sites of EE2 were mainly located within site I in the subdomain IIA of BSA.

The investigation focused on the interaction between bovine serum albumin (BSA) and the biologically active coumarin derivatives 4-(5-amino-[1,3,4]thiadiazol-2-ylsulfanylmethyl)-7-methoxy-chrome-2-one (1) and 4-(5-amino-[1,3,4]thiadiazol-2-ylsulfanyl methyl)-7-methyl-chrome-2-one (2). Molecular docking approaches, synchronous fluorescence spectroscopy, UV–Vis spectroscopy, circular dichroism (CD) spectra and fluorescence spectroscopy were among the multispectroscopic methods used to study the interaction between BSA and coumarin derivatives. The examined coumarin compounds’ interaction with BSA yielded a static quenching mechanism for fluorescence. Values for the binding constant (K b) and quenching constant (K q) for BSA–coumarin derivatives have been calculated using the Stern–Volmer equation. A change in the tryptophan residue of BSA was seen in its surroundings using synchronous fluorescence quenching investigations. The potential of the compounds under investigation to bind BSA was examined, and it was found that each compound had around one binding site. According to the free energy estimate, there is a spontaneous and very favorable binding interaction between BSA and test compounds. Using the Forster energy transfer theory, the binding average distance between BSA and the chemicals under investigation was found. In conjunction with the findings of CD spectral and fluorescence investigations, it shown that compound 2 has a higher affinity for BSA than compound 1. Molecular docking studies and spectroscopic experimental data are found to be in good agreement. The binding pocket for the development of the ligand–protein complex through hydrophobic and hydrogen bonding interactions was identified by the molecular docking investigation. Furthermore, the results of the Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) prediction and drug-likeness analysis demonstrated the medicinal chemistry characteristics and drug-likeness of these compounds.

To investigate the characteristics of dissolved organic matter (DOM) in snow, snow samples collected during two snow eventy at typical sites in different districts of Beijing were characterized by UV-vis spectroscopy, three-dimensional fluorescence spectroscopy and synchronous fluorescence spectroscopy. The results revealed that the concentrations of dissolved organic carbon (DOC) at different sites varied widely, which might be attributed to the different nature of underlying surface materials. DOM in snow samples was composed of organic compounds with lower molecular weight and less aromatic structures, which can be possibly attributed to small amount of fulvic acid produced by biological activity. The information obtained from synchronous fluorescence spectra showed that some protein material and aromatic compounds were also found in the DOM. The investigation of spectroscopic properties can facilitate further insight into the interaction between DOM and co-existing pollutants, and also can provide basic information on the efficient utilizations of snow.

Characterizing the binding interaction between antimalarial artemether (AMT) and bovine serum albumin (BSA): Spectroscopic and molecular docking methods

Study on total luminescence spectra. Application of the Monte-Carlo method to three-dimensional synchronous fluorescence spectrometry

Classification of binding sites for Al(III) in fulvic acids extracted from leaf litters and soils by synchronous fluorescence spectroscopy and multidimensional chemometric analysis

The interaction between troxerutin and pepsin was studied by multispectral method and molecular docking simulation

The binding of malathion to human serum albumin (HSA) in the presence of silver nanoparticles (AgNPs) was investigated for the first time by multiple spectroscopic methods such as fluorescence quenching, fluorescence resonance energy transfer (FRET), circular dichroism, red-edge excitation shift (REES), synchronous fluorescence and three dimensional fluorescence spectroscopy under physiological conditions .The results indicated that binding of malathion to HSA induced fluorescence quenching through static mechanism. The number of binding sites was calculated by double logarithmic equation. Changes in the micro-environment of the fluorophore residues were also probed by synchronous fluorescence spectroscopy and REES. Changes of secondary structure of HSA in HSA–malathion complex was verified by circular dichroism approach in the presence of AgNPs that showed the electrostatic interaction changes in the protein structure. The binding average distance (r) between the donor (HSA) and the acceptor (malathion) was measured and found to be 1.63 nm according to the Forster’s theory of non-radiation energy transfer which was <7 nm confirmed the existence of static quenching in the presence of AgNPs. The conformational changes of HSA by three-dimensional fluorescence spectroscopy were studied. By comparing the resonance light scattering in the binary and ternary systems, we could estimate the effect of AgNPs on the precipitation of the malathion on the HSA. Generally we have discussed the toxicity reduction effect of malathion in food industrial by the results of spectroscopy techniques.

The interaction between strictosamide (STM) and human serum albumin (HSA) was investigated by fluorescence spectroscopy, synchronous fluorescence spectroscopy, three-dimensional fluorescence spectroscopy, ultraviolet-visible absorption spectroscopy, circular dichroism spectroscopy and molecular modeling under physiological pH 7.4. STM effectively quenched the intrinsic fluorescence of HSA via static quenching. The binding site number n and apparent binding constant K(a) were determined at different temperatures by fluorescence quenching. The thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS) for the reaction were calculated as -3.01 kJ/mol and 77.75 J/mol per K, respectively, which suggested that the hydrophobic force played major roles in stabilizing the HSA-STM complex. The distance r between donor and acceptor was obtained to be 4.10 nm according to Förster's theory. After the addition of STM, the synchronous fluorescence and three-dimensional fluorescence spectral results showed that the hydrophobicity of amino acid residues increased and the circular dichroism spectral results showed that the α-helix content of HSA decreased (from 61.48% to 57.73%). These revealed that the microenvironment and conformation of HSA were changed in the binding reaction. Furthermore, the study of molecular modeling indicated that STM could bind to site I of HSA and the hydrophobic interaction was the major acting force, which was in agreement with the binding mode study.