scholarly journals Hydrophobic interactions of phenoxazine modulators with bovine serum albumin

2000 ◽  
Vol 112 (1) ◽  
pp. 51-61 ◽  
Author(s):  
H. N. Kalpana ◽  
B. C. Channu ◽  
Chhabil Dass ◽  
P. J. Houghton ◽  
K. N. Thimmaiah
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Hydrophobic Interactions

scholarly journals The study on the interaction of Epigallocatechin gallate with bovine serum Albumin

2020 ◽  
pp. 1-9
Author(s):  
Gombosuren Davaadulam ◽  
Maamuu Tamara ◽  
Nyamaa Gerelsuren
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Hydrophobic Interactions ◽  
Epigallocatechin Gallate ◽  
Docking Simulation ◽  
Entropy Change ◽  
Ligand Docking ◽  
Number Of Binding Sites ◽  
Hoff Equation

In this study, we investigated the interaction of epigallocatechin gallate (EGCG) with bovine serum albumin (BSA) by fluorescence method and protein‐ligand docking. We separated EGCG from green tea using the chromatographic method and analyzed structural activity relationships of the EGCG. The results show that EGCG is a strong quencher of BSA fluorescence and binds with BSA with high affinity. The binding parameters (binding constant, the number of binding sites) were determined by the Ward equation. From the thermodynamic parameters, calculated according to the van’t Hoff equation, the enthalpy change ΔH°, and entropy change ΔS° were found to be -22.67 kJ/mol and 14.92 J/mol/K, respectively. These values suggest that apart from an initial hydrophobic association, the complex is held together by electrostatic and hydrogen bonding. In the docking simulation, the lowest free energies for the interaction of EGCG with tryptophan residues was −21.92kJ/mol (Trp134) and −24.7 kJ/mol (Trp213). The binding between EGCG and BSA consists of hydrogen bonds (Trp213) and hydrophobic interactions (Trp134).

Thermodynamics investigation of a series of metalloporphyrazine-bovine serum albumin complexes

2007 ◽  
Vol 11 (08) ◽  
pp. 556-565 ◽  
Author(s):  
A-Khalegh Bordbar ◽  
Hamid Dezhampanah ◽  
Mozaffar Asadi ◽  
Elham Safaei ◽  
Nasrin Sohrabi ◽  
...  
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Hydrophobic Interactions ◽  
Fluorescence Emission ◽  
Resonance Light Scattering ◽  
Complex Model ◽  
Aggregate Formation ◽  
Fluorescence Studies ◽  
Induced Aggregation

The equilibrium binding of the tetra-cationic complexes ( N , N ′, N ″, N ‴-tetra-methyltetra-2,3-pyridinoporphyrazinato)copper(II), ([ Cu (2,3- TMTPPA )]4+), ( N , N ′, N ″, N ‴-tetra-methyltetra-3,4-pyridinoporphyrazinato)copper(II), ([ Cu (3,4- TMTPPA )]4+), (( N , N ′, N ″, N ‴-tetra-methyltetra-3,4-pyridinoporphyrazinato)cobalt(II), ([ Co (3,4- TMTPPA )]4+) and (( N , N ′, N ″, N ‴-tetra-methyltetra-3,4-pyridinoporphyrazinato)zinc(II), ([ Zn (3,4- TMTPPA )]4+) with bovine serum albumin (BSA) has been studied in phosphate buffer pH = 7.0 and at various temperatures using multi-spectroscopy techniques. The results of resonance light scattering (RLS) studies represent no aggregate formation of porphyrazine in the surface of BSA and low tendency of these porphyrazine for aggregate formation. The binding constants and binding stoichiometries were determined by analyzing of optical absorption spectra of porphyrazine complexes at various concentration of BSA using SQUAD software. The results show that the best fitting corresponds to a 1:1 complex model between BSA and porphyrazines. The thermodynamic parameters were calculated by van't Hoff equation at various temperatures. The data indicate that the process is entropy driven suggesting that hydrophobic interactions play a considerable role in the complex formation. The binding of porphyrazine complexes to BSA quenches fluorescence emission of BSA via a dynamic mechanism and the quenching process obeys a linear Stern-Volmer relationship. The average aggregation number of BSA, which has been calculated from the analysis of fluorescence quenching data, indicates the absence of any porphyrazine induced aggregation of BSA due to its interaction with porphyrazine complexes. Fluorescence studies also indicate that porphyrazine is bound to site I of BSA placed in sub-domain IIA, where tryptophan 214 is located.

scholarly journals Emissive Enhancement of the Singlet Oxygen Chemiluminescence Probe after Binding to Bovine Serum Albumin

Molecules ◽  
2019 ◽  
Vol 24 (13) ◽  
pp. 2422 ◽  
Author(s):  
Miranda-Apodaca ◽  
Hananya ◽  
Velázquez-Campoy ◽  
Shabat ◽  
Arellano
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Singlet Oxygen ◽  
Binding Sites ◽  
Bovine Serum ◽  
Hydrophobic Interactions ◽  
Titration Calorimetry ◽  
Reaction Yield ◽  
Cell Penetrating Peptide ◽  
Thermal Stability Of

A chemiluminescence probe for singlet oxygen 1O2 (SOCL) was investigated in phosphate buffer saline (PBS), either in the absence of proteins or containing bovine serum albumin (BSA). In the protein-free PBS, the reactivity of SOCL for methylene blue (MB)-photosensitized 1O2 was found to be moderate or low. The reaction yield increased with temperature and/or concentration of dissolved molecular oxygen. Unexpectedly, the presence of BSA boosted both the emissive nature and the thermal stability of the phenoxy-dioxetane intermediate formed in the chemiexcitation pathway. Isothermal titration calorimetry showed that SOCL has a moderate binding affinity for BSA and that entropy forces drive the formation of the SOCL-BSA complex. A model with two identical and independent binding sites was used to fit the binding isotherm data. Co-operative binding was observed when MB was present. Local viscosity factors and/or conformational restrictions of the BSA-bound SOCL phenoxy-dioxetane were proposed to contribute to the formation of the highly emissive benzoate ester during the chemically initiated electron exchange luminescence (CIEEL) process. These results led us to conclude that hydrophobic interactions of the SOCL with proteins can modify the emissive nature of its phenoxy-dioxetane, which should be taken into account when using SOCL or its cell-penetrating peptide derivative in living cells.

The Investigation of the Interaction between Daidzin and Bovine Serum Albumin by Fluorescence Spectroscopy

2014 ◽  
Vol 664 ◽  
pp. 402-409
Author(s):  
Qing Ming Wang ◽  
Jia Liu ◽  
Tian Xing Zhang ◽  
Feng Zhu ◽  
Xin Hui Tang
Keyword(s):  
Bovine Serum Albumin ◽  
Hydrogen Bonds ◽  
Fluorescence Quenching ◽  
Fluorescence Spectroscopy ◽  
Serum Albumin ◽  
Binding Constant ◽  
Bovine Serum ◽  
Hydrophobic Interactions ◽  
Binding Constants ◽  
Apparent Binding Constant

We investigated the mutual interaction of daidzin with bovine serum albumin (BSA) by fluorescence spectroscopy. The results revealed that daidzin cause the fluorescence quenching of BSA through a static quenching procedure. The Stern-Volmer quenching constant (Ksv) were calculated at different temperature. The binding site (n), apparent binding constant (Ka) and corresponding thermodynamic parameters △Go, △Ho, △Sowere calculated and the van der Waals interaction, hydrogen bonds and hydrophobic interactions play an important role in stabilizing the complex. Besides, we also studied the effect of Cu2+, Ni2+, Mn2+and Co2+on the binding constants between daidzin and BSA, it is shows that the binding of BSA and daidzin is strengthened in the presence metal ions.

scholarly journals Peculiarities of thermal aggregation of bovine serum albumin in the presence of strong polyelectrolytes

2020 ◽  
Vol 63 (9) ◽  
pp. 35-42
Author(s):  
Natalia N. Smirnova ◽  
◽  
Kirill V. Smirnov ◽  
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Polymer Electrolyte ◽  
Sodium Salt ◽  
Bovine Serum ◽  
Temperature Increase ◽  
Hydrophobic Interactions ◽  
Maximum Yield ◽  
Maximum Output ◽  
Protein Molecules

The influence of temperature on bovine serum albumin (BSA) aggregation in aqueous solutions in the presence of poly-N,N-dimethyl-N,N-diallylammonium chloride (PDMDAAC) and the sodium salt of carboxymethylcellulose (CMC) was studied. It was shown that protein-polyelectrolyte complexes (PPC) form because of macromolecular reactions that are stabilized mainly by electrostatic forces. To characterize the PPC composition the φ parameter was used. This parameter is defined as the ratio of the concentration of ionic groups of polyelectrolyte per protein molecules. It was studied that when in an interpolyelectrolyte reaction, a sufficiently high degree of transformation occurs the polymer electrolyte initiates aggregation of protein molecules. As the temperature increases, the initiating role of the polymer electrolyte increases due to an increase in the intensity of hydrophobic interactions. Using the method of spectrophotometry, it was found that, depending on the nature of the polymer electrolyte, insoluble complexes of bovine serum albumin are formed when the pH parameter is above or below the isoelectric point of the protein, when its macromolecules are negatively or positively charged. In the presence of poly-N,N-dimethyl-N,N-diallylammonium chloride, the intensive formation of aggregates and their rapid precipitation in the form of flakes at pH > 7.0 was observed when the temperature increased to 60 °C. The maximum yield of the product of the interpolyelectrolyte reaction bovine serum albumin – sodium salt of carboxymethylcellulose was detected at pH ≤ 4.0. A temperature increase up to 60 °C, in this case, was not accompanied by intensive flocculation. Under optimal composition and interaction conditions, the degree of transformation in the BSA – PDMDAAX and BSA – CMC reactions is ~0.93 and 0.9, respectively, and decreases by ~5-7% with an increase in temperature to 60 °C. It was shown that for the same BOD composition (the ratio of components in the [CMC]/[BSA] complex = 0.1 g/g), an increase in temperature from 25 to 60 °C leads to the formation of particles that increase in size from 1 mcm to 5 mcm. The temperature increase leads to a change in composition of BOD, corresponding to its maximum output as a interpolyelectrolyte reactions product: for complex with PDMDAAC at T = 25, 40 and 60 °C, the φ value is 70, 60, 15; for the complex with the CMC – 60, 50, 20.

scholarly journals A Study of the Antibacterial Activities and the Mode of Action of L-Methionine and L-Cystine Based Surfactants and their Interaction with Bovine Serum Albumin Using Fluorescence Spectroscopy and in Silico Modelling

2021 ◽  
Vol 12 (6) ◽  
pp. 7356-7375
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Hydrophobic Interactions ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Resistant Bacteria ◽  
Binding Studies ◽  
Gram Positive ◽  
Gram Negative

Surfactants are versatile excipients that are commonly employed in diverse pharmaceutical formulations given their broad range of antimicrobial activities. Sulfur-based amino acid surfactants are promising candidates as substitutes for conventional antibacterial agents in light of the current antibiotic resistance crisis. Dodecyl esters of the free amine (SURF1), cationic ester hydrochloride (SURF2), and quaternary ammonium (QUAT3) derivatives of methionine, and the Gemini diester of cystine (GEM4) were synthesized and evaluated for antibacterial activity against Gram-positive and Gram-negative pathogens. All surfactants displayed moderate to high antibacterial activities, particularly on Gram-positive bacteria, with QUAT3 showing the highest activity. Among Gram-negative bacteria, QUAT3, GEM4, and SURF2 were mostly active towards K. pneumoniae with minimum inhibitory concentrations (MIC) ranging from 0.004 to 0.441 mM. QUAT3 and GEM4 displayed a bacteriostatic behavior similar to that of tetracycline, as assessed by broth macrodilution assays. Fluorescence binding studies with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) revealed that the antibacterial activities could be attributed to a combination of electrostatic and hydrophobic interactions. Bovine serum albumin (BSA) fluorescence and molecular docking studies indicated that SURF1 and QUAT3 interact mainly via van der Waals' forces and hydrogen bonding while SURF2 binds through hydrophobic interactions. QUAT3, which displays broad-spectrum activity, has the potential to combat drug-resistant bacteria.

scholarly journals Dominant effect of ethanol in thermal destabilization of bovine serum albumin in the presence of sucrose

2009 ◽  
Vol 23 (5-6) ◽  
pp. 265-270 ◽  
Author(s):  
V. Sathya Devi ◽  
Obiora O. Chidi ◽  
Denis Coleman
Keyword(s):  
Thermal Stability ◽  
Bovine Serum Albumin ◽  
Binary Mixture ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Hydrophobic Interactions ◽  
Dominant Effect ◽  
Thermal Melting ◽  
Phosphate Buffered Saline ◽  
Circular Dichroïsm

The thermal melting of bovine serum albumin (BSA) in the presence of excipients like ethanol and sucrose was studied by circular dichroism spectroscopy at physiological pH in phosphate buffered saline. Calculated apparentTmvalues were used to assess the thermal stability using two state fitted experimental curves. 0.5 M sucrose stabilized the BSA indicated by the increase inTmof ∼8°C when compared to theTmof the same solution measured in the absence of sucrose. Conversely, in the presence of varying concentrations of ethanol (2–20%), the protein was destabilized by a decrease of ∽3–10°C ofTm. In the binary mixture of sucrose and ethanol, theTmvalues showed that ethanol dominantly destabilized BSA in the presence of sucrose, possibly by weakening the hydrophobic interactions in the protein.

scholarly journals Sorptive and Separation Properties of Ultrafiltration Membranes on the Basis of Sulfonate-Containing Polyamide with Respect to Bovine Serum Albumin

2012 ◽  
Vol 15 (1) ◽  
pp. 51
Author(s):  
N.N. Smirnova ◽  
Yu.A. Fedotov ◽  
I.A. Nebukina
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Hydrophobic Interactions ◽  
Sorption Isotherms ◽  
Aromatic Polyamide ◽  
Static Mode ◽  
Ionic Groups ◽  
Maximum Sorption ◽  
Membrane Protein Interaction

<p>Investigation of sorption of bovine serum albumin in the static mode and in ultrafiltration conditions by membranes produced from statistic copolymers of aromatic polyamides synthesized by polycondensation of the sodium salt of 4, 4/-diaminodiphenylamine-2-sulfo-acid and m-phenylenediamine in various ratios with chloroanhydride of isophthalic acid has been carried out. Interconnection has been established between the charge of protein macromolecules, concentration of fragments containing ionic groups in the aromatic polyamide and sorptive, separation and transport characteristics of membranes on its basis. It has been shown that dominant forces that determine membrane/protein interaction in the systems under consideration are coulomb forces, but the contribution of hydrophobic interactions is also significant. The results of mathematical processing of experimental data indicate that there is a good compliance of sorption isotherms with Langmuir’s model. Depending on the concentration of fragments containing ionic groups in the polyamide and pH of the solution, the calculated values of maximum sorption in sorbent/sorbate systems under consideration vary in the range of 0.028 to 0.338 mg/cm<sup>2</sup>. Dynamic investigations have shown that selectivity of the membranes is 85 to 98%. To assess the sorptive activity of the membranes in the course of ultrafiltration, indicators of sorption and sorptive losses calculated on the basis of the ratio of the change of mass content of protein in the process of filtration to the initial value have been used. Depending on the material used to produce the membrane and pH of the solution being filtered, sorptive losses range from 5 to 33%. Their minimum value is observed when pH is higher than the isoelectric point of the protein, i.e. in the field where protein macromolecules and the surface of the membrane have like charges.</p>

Improvement of an artificial test substrate technique for evaluation of em immunocytochemical labeling

1987 ◽  
Vol 45 ◽  
pp. 762-763
Author(s):  
G. D. Gagne ◽  
M. F. Miller
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Artificial Substrate ◽  
Chemical Fixation ◽  
As If

We recently described an artificial substrate system which could be used to optimize labeling parameters in EM immunocytochemistry (ICC). The system utilizes blocks of glutaraldehyde polymerized bovine serum albumin (BSA) into which an antigen is incorporated by a soaking procedure. The resulting antigen impregnated blocks can then be fixed and embedded as if they are pieces of tissue and the effects of fixation, embedding and other parameters on the ability of incorporated antigen to be immunocyto-chemically labeled can then be assessed. In developing this system further, we discovered that the BSA substrate can also be dried and then sectioned for immunolabeling with or without prior chemical fixation and without exposing the antigen to embedding reagents. The effects of fixation and embedding protocols can thus be evaluated separately.

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