Time-resolved fluorescence data of the (HSA-PPIX) TF and (HSA-PPIX) TF/drug complexes (λ_ex = 295 nm, λ_em = 345 nm, pH 7.4, T = 298 K).

<p>Time-resolved fluorescence data of the (HSA-PPIX) TF and (HSA-PPIX) TF/drug complexes (λ_ex = 295 nm, λ_em = 345 nm, pH 7.4, T = 298 K).</p

Three-dimensional fluorescence spectra characteristic of the interaction of (HSA-PPIX)-TF in the absence and presence of LMF.

<p>Three-dimensional fluorescence spectra characteristic of the interaction of (HSA-PPIX)-TF in the absence and presence of LMF.</p

Comparison of the binding constants of the (HSA-PPIX) LMF and [(HSA-PPIX)-TF] LMF systems before and after the addition of the site probe.

<p>Comparison of the binding constants of the (HSA-PPIX) LMF and [(HSA-PPIX)-TF] LMF systems before and after the addition of the site probe.</p

Molecular modeling of the interaction of LMF with the [(HSA-PPIX)-TF] complex, (A) and the second site of the interaction of LMF with [(HSA-PPIX)-TF] (B), represented as a solid ribbon, colored by secondary structure, LMF represented as sticks.

<p>The docking position of LMF to the protein is highlighted. LMF was docked in sub-domain IIIB of (HSA-PPIX). The distance between the binding site candidates of LMF to Trp is also illustrated. The hydrogen bonds between LMF and (HSA-PPIX) are represented as green dashed lines.</p

Stern-Volmer quenching constants of the various complexes with LMF at λ_ex = 280 nm.

<p>Stern-Volmer quenching constants of the various complexes with LMF at λ_ex = 280 nm.</p

Effect of LMF on the zeta potential of (HSA-PPIX)-LMF (open circle), and [(HSA-PPIX)-TF]-LMF (filled circle) in pH 7.4.

<p>Effect of LMF on the zeta potential of (HSA-PPIX)-LMF (open circle), and [(HSA-PPIX)-TF]-LMF (filled circle) in pH 7.4.</p

Second derivative of the Trp emission spectra of (HSA-PPIX)-LMF (A) and [(HSA-PPIX)-TF]-LMF (B).

<p>[LMF] = 0.05 mM, [(HSA-PPIX)-TF] = [HSA-PPIX] = 4.5×10⁻³ mM.</p

Phase diagram for the (HSA–PPIX)-LMF system (A) and the [(HSA-PPIX)-TF]-LMF system (B).

<p>[LMF] = 0.05 mM, [(HSA-PPIX)-TF] = [HSA-PPIX] = [TF] = 4.5×10⁻³ mM. λ_ex = 295 nm; pH 7.4, T = 298K.</p

Fluorescence emission spectra of the protein–drug systems in the presence of various concentrations of LMF for the (HSA–PPIX) system (A) and (HSA–PPIX)-TF system (B), λ_ex = 280 nm.

<p>Fluorescence emission spectra of the protein–drug systems in the presence of various concentrations of LMF for the (HSA–PPIX) system (A) and (HSA–PPIX)-TF system (B), λ_ex = 280 nm.</p

Probing the interaction behavior of Nano-Resveratrol with α-lactalbumin in the presence of β-lactoglobulin and β-casein: spectroscopy and molecular simulation studies

The main purpose of this research was to evaluate the role of α-lactalbumin (α-LA), β-lactoglobulin (β-LG), and β-Caseins (β-CN) in the binding interaction between Nano Resveratrol (Nano Res), as binary and ternary systems. This investigation was fulfilled through the application of multi-spectroscopic, transmission electron microscopy (TEM), field emission scanning electron microscope (FE-SEM), conductometry, isothermal titration calorimetry (ITC), and molecular dynamics (MD) simulation techniques. Fluorescence spectroscopy observations illustrated the effectiveness of Nano Res throughout the quenching of α-LA, (α-LA-β-LG), and (α-LA-β-CN) complexes, confirming the occurrence of interaction through the combination of static and dynamic mechanisms. An enhancement in the temperature of all three complexes caused a decrease in their Ksv and Kb values, which indicates the static and dynamic behavior of their interactions. The obtained thermodynamic parameters proved the dominance of electrostatic interaction as the binding force of both binary and ternary systems. The observed properties of Tyr or Trp residues in proteins through the data of synchronous spectroscopy at Δλ = 15 and 60 nm, respectively, demonstrated the closer positioning of (α-LA-β-CN) complex to the proximity of Trp residues when compared to the two other cases. According to the resonance light scattering (RLS) measurements, the detection of a much greater RLS intensity in (α-LA-β-CN) Nano Res complex suggested the production of a larger complex. Furthermore, the conductometry outcomes displayed an increase in molar conductivity and therefore approved the occurrence of interaction between Nano Res and proteins in both binary and ternary systems. The spherical shape of Nano Res was confirmed through the results of FE-SEM and TEM analyses. The conformational changes of proteins throughout the binding of Nano Res was evaluated by circular dichroism (CD) technique, while molecular docking and MD simulations affirmed the binding of Nano Res to α-LA, (α-LA-β-LG), and (α-LA-β-CN) complexes as binary and ternary systems. These In Silico study data confirm the results of in vitro assessments. The occurrence of changes in the secondary structure of β-galactosidase was implied through the increased enzyme catalytic activity induced by the interaction of different lactose concentrations. Communicated by Ramaswamy H. Sarma</p