Biomolecular interaction study of hydralazine with bovine serum albumin and effect ofβ-cyclodextrin on binding by fluorescence, 3D, synchronous, CD, and Raman spectroscopic methods

Investigations of the Interaction Mechanism Between Orphenadrine Hydrochloride and Bovine Serum Albumin by Spectroscopic and Voltammetric Techniques

The interaction of orphenadrine hydrochloride (ORD) with the model protein, bovine serum albumin (BSA), was investigated using a variety of spectroscopic techniques such as steady-state fluorescence, ultraviolet-visible, Fourier transform infrared, 3-D spectroscopy, and electrochemical methods under physiological conditions. Stern-Volmer plots were used to calculate fluorescence quenching at various temperatures. The findings point to a static quenching mechanism between ORD and BSA. At various reaction times, the binding sites (n) and binding constants (K) of ORD to BSA were recorded. Thermodynamic parameters ∆H0, ∆S0 and ∆G0 between ORD and BSA were calculated and reported. The average binding distance (r) between the donor (BSA) and acceptor (ORD) molecules was predicted using Förster's theory. Three-dimensional fluorescence spectra, Fourier transform infrared spectra, and synchronous fluorescence studies all supported the alternations in protein structure following the interaction with ORD. A displacement study using site probes such as warfarin, ibuprofen, and digitoxin confirmed ORD binding at Sudlow's site I of BSA. The effect of common metal ions such as Cu2+, Ni2+, Ca2+, Co2+, and Zn2+ on binding constant values was investigated and reported.

Potential ability of different types of cyclodextrins to modulate the interaction between bovine serum albumin and 1-hydroxypyrene

Hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) can bind with functional biomacromolecules and thus cause toxic effects in vivo. Four types of cyclodextrins (CDs) were selected to explore their potential ability to regulate the bindings between 1-hydroxypyrene (1-OHPyr) and bovine serum albumin (BSA) using multi-spectroscopic methods combined with molecular docking. The results showed that the four CDs caused varied modulating effects on the binding of BSA with 1-OHPyr, and the effects of γ-CD and (2-hydroxypropyl)-β-CD (HPCD) are the most significant. Specifically, γ-CD and HPCD could significantly reduce the binding affinity between 1-OHPyr and BSA, inhibit the micro-environmental changes of tryptophan residues, and slightly recover the helicity of BSA. The interactions and inclusion behavior of CDs with 1-OHPyr was the main reason why CDs could affect the binding of 1-OHPyr to BSA. The results indicated that γ-CD and HPCD might have potential application value in regulating the toxic effects of OH-PAHs.

Albumin Protects Lung Cells against Acrolein Cytotoxicity and Acrolein-Adducted Albumin Increases Heme Oxygenase 1 Transcripts

Albumin is an abundant protein in the lung lining fluid that forms an interface between lung epithelial cells and the external environment. In the lung, albumin can be targeted for adduction by inhaled acrolein. Acrolein, an α,β-unsaturated aldehyde, reacts with biomolecules via Michael addition at the β-carbon or Schiff base formation at the carbonyl carbon. To gain insight into acrolein's mode of action, we investigated in vitro albumin-acrolein reactivity and the consequence of albumin adduction by acrolein on cytotoxicity and transcript changes in NCI-H441 and human airway epithelial cells (HAEC). Albumin protected NCI-H441 cells from acrolein toxicity. In addition, albumin inhibited acrolein-induced increase of transcripts associated with cellular stress response, activating transcription factor 3 (ATF3), and antioxidant response, heme oxygenase 1 (HMOX1) in HAEC cells. Acrolein-adducted albumin itself increased HMOX1 transcripts but not ATF3 transcripts. The HMOX1 transcript increase was inhibited by hydralazine, a carbonyl scavenger, suggesting that the carbonyl group of acrolein-adducted albumin mediated HMOX1 transcript increase. In acutely exposed C57BL/6J mice, bronchoalveolar lavage protein carbonylation increased. Acrolein-adducted albumin Cys34 was identified by nLC-MS/MS. These findings indicate that adduction of albumin by acrolein confers a cytoprotective function by scavenging free acrolein, decreasing a cellular stress response, and inducing an antioxidant gene response. Further, these results suggest that β-carbon reactivity may be required for acrolein's cytotoxicity and ATF3 transcript increase, and the carbonyl group of acrolein-adducted albumin can induce HMOX1 transcript increase.

Spectroscopic, thermodynamic and molecular docking studies of bovine serum albumin interaction with ascorbyl palmitate food additive

Introduction: Ascorbyl palmitate (AP) is an example of natural secondary food antioxidant, which has been used for oxidative rancidity prevention in food industry. In this study, the interaction of AP with bovine serum albumin (BSA) was investigated.

Methods: The mechanism of BSA interaction with AP was investigated using spectroscopic methods (UV-Vis, fluorescence). The thermodynamic parameters including enthalpy change (ΔH), entropy change (ΔS), and Gibb’s free energy (ΔG) were calculated using Van’t Hoff equation at different temperatures.

Results: The experimental results showed that UV-Vis absorption spectra of BSA decreased upon increasing AP concentration, indicating that the AP can bind to BSA. Formation of the AP-BSA complex was approved by quenching of fluorescence and the quenching mechanism was found to be resultant from dynamic procedure. The positive values of both ΔH and ΔS showed that hydrophobic forces were the major binding forces. The negative value of ΔG demonstrated that AP interacts with BSA spontaneously. Molecular docking results confirmed that AP binds to BSA through hydrophobic forces.

Conclusion: The attained results showed that AP can bind to BSA and effectively distributed into the bloodstream.

Cisplatin combination drugs induce autophagy in HeLa cells and interact with HSA via electrostatic binding affinity

Cisplatin combination drugs induce autophagy in HeLa cells and interact with HSAviaelectrostatic binding affinity.

Insights into the molecular interaction between two polyoxygenated cinnamoylcoumarin derivatives and human serum albumin

Drug–protein interactions based on the thermodynamics approach, curve resolution analysis and computational methods at molecular levels.