scholarly journals Effect of Tetraphenylborate on Physicochemical Properties of Bovine Serum Albumin

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6565
Author(s):  
Ola Grabowska ◽  
Małgorzata M. Kogut ◽  
Krzysztof Żamojć ◽  
Sergey A. Samsonov ◽  
Joanna Makowska ◽  
...  
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Binding Sites ◽  
Bovine Serum ◽  
Titration Calorimetry ◽  
Scanning Calorimetry ◽  
Experimental Conditions ◽  
Potential Binding ◽  
Cacodylate Buffer ◽  
Helical Content

The binding interactions of bovine serum albumin (BSA) with tetraphenylborate ions ([B(Ph)4]−) have been investigated by a set of experimental methods (isothermal titration calorimetry, steady-state fluorescence spectroscopy, differential scanning calorimetry and circular dichroism spectroscopy) and molecular dynamics-based computational approaches. Two sets of structurally distinctive binding sites in BSA were found under the experimental conditions (10 mM cacodylate buffer, pH 7, 298.15 K). The obtained results, supported by the competitive interactions experiments of SDS with [B(Ph)4]− for BSA, enabled us to find the potential binding sites in BSA. The first site is located in the subdomain I A of the protein and binds two [B(Ph)4]− ions (logK(ITC)1 = 7.09 ± 0.10; ΔG(ITC)1 = −9.67 ± 0.14 kcal mol−1; ΔH(ITC)1 = −3.14 ± 0.12 kcal mol−1; TΔS(ITC)1 = −6.53 kcal mol−1), whereas the second site is localized in the subdomain III A and binds five ions (logK(ITC)2 = 5.39 ± 0.06; ΔG(ITC)2 = −7.35 ± 0.09 kcal mol−1; ΔH(ITC)2 = 4.00 ± 0.14 kcal mol−1; TΔS(ITC)2 = 11.3 kcal mol−1). The formation of the {[B(Ph)4]−}–BSA complex results in an increase in the thermal stability of the alfa-helical content, correlating with the saturation of the particular BSA binding sites, thus hindering its thermal unfolding.

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.

scholarly journals Evaluación del método dilución neutralización aplicado a un desinfectante según la Norma Técnica Colombiana 5473 de 2007

2012 ◽  
Vol 17 (1) ◽  
pp. 72
Author(s):  
Janeth Arias-Palacios ◽  
Libardo Hernandez-Esquivel ◽  
Juan Carlos Marín-Díaz ◽  
Natalia Navarro-Peña ◽  
Natalia Santos-Arévalo
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Key Words ◽  
Bactericidal Activity ◽  
Bovine Serum ◽  
Enterococcus Hirae ◽  
Experimental Conditions ◽  
Logarithmic Reduction

<strong>Objective</strong>. Evaluate the dilution-neutralization method proposed in the Colombian Technical Norm 5473/07, by using a gel, alcoholbased disinfectant. <strong>Materials and methods</strong>. This study was done using Pseudomonas aeruginosa ATCC 15442, Staphylococcus aureus ATCC 6538, and Enterococcus hirae ATCC 10541 as the assay microorganisms. The study was carried out at 20±1°C as obligatory temperature and additionally at 36±1°C. Four contact times between microorganisms and the disinfectant were evaluated (0, 2, 5 and 10 minutes). The assay was done both under clean conditions (0.3 g/L of bovine serum albumin), and unclean conditions (3 g/L of bovine serum albumin and 3g/L of sheep erythrocytes). <strong>Results</strong>. The implementation of this method produced precise results in all of the six<br />repetitions used during the assay. The obtained results demonstrated a logarithmic reduction higher than five, demonstrating the bactericidal activity exerted by the disinfectant on the control microorganisms. The established experimental conditions and methodology did not affect negatively the growth of any of the strains of microorganisms. Similarly, the neutralizing used did not inhibit the development of the microorganisms of the assay.<strong> Conclusions</strong>. The method was verified by means of the fulfillment of the limits set by the rule. Our results suggest that the method evaluated by means of the implementation of the protocol established in the Colombian Technical Norm 5473/07, allows evaluating the effectiveness of a disinfectant under selected and controlled experimental conditions.<br /><br /><strong>Key words</strong>: disinfection, clean conditions, unclean conditions, dilution-neutralization method, logarithmic reduction.

Chemotactic properties, cellular binding and uptake of peptides and peptide derivatives: studies with Tetrahymena thermophila

1992 ◽  
Vol 103 (2) ◽  
pp. 565-570
Author(s):  
V. Leick
Keyword(s):  
Bovine Serum Albumin ◽  
Cell Surface ◽  
Serum Albumin ◽  
Binding Sites ◽  
Bovine Serum ◽  
Tetrahymena Thermophila ◽  
Chemotactic Peptide ◽  
Dansyl Group ◽  
Peptide Derivatives

Receptor-mediated binding of leukocyte chemotactic peptide, N-formylMet-Leu-Phe (fMLP), occurs in the ciliated protozoon Tetrahymena thermophila. In vivo labelling of the cells with N-formylMet-Leu-[3H]Phe ([3H]fMLP) shows that the cells bind the ligand with high affinity (KD = 4 × 10(−9) M to 1 × 10(−8) M). Moreover, Scatchard transformations of the binding data show that there are about 5 × 10(5) binding sites per cell on the cell surface. Two fluorescent derivatives of leukocyte chemotactic peptide, N-dansylMet-Leu-Phe (dansMLP) and N-formylMet-Leu-Phe-(N-dansyl-)Lys (fMLPdanLys) compete for the N-formylMet-Leu-Phe (fMLP) binding sites on the cell surface. Moreover, both derivatives have retained significant chemoattracting potentials. Fluorescence from dansMLP, but not from fMLPdansLys and dansyl-beta-endorphin, is internalized preferentially into small vesicles. The differences may, however, reflect that the fluorescence from the dansyl group is strongly quenched by a hydrophilic microenvironment when using the two latter peptide derivatives. In contrast, the dansyl group from dansMLP must be assumed to be embedded in a hydrophobic microenvironment in the vesicular membrane or membrane protein. Rhodamine-labelled bovine serum albumin, egg albumin and cytochrome c as well as dansylated bovine serum albumin, which are poor chemoattractants, are preferentially seen to be internalized into large vesicles (food vacuoles).

Albumin reduces basement membrane hydraulic conductance in part due to arginyl side groups

1995 ◽  
Vol 269 (5) ◽  
pp. H1514-H1521 ◽  
Author(s):  
M. A. Katz ◽  
M. L. La Marche
Keyword(s):  
Extracellular Matrix ◽  
Bovine Serum Albumin ◽  
Basement Membrane ◽  
Serum Albumin ◽  
Protective Effect ◽  
Binding Sites ◽  
Bovine Serum ◽  
Hydraulic Conductance ◽  
Experimental Control ◽  
Low Concentrations

Albumin reduces capillary hydraulic conductance (Lp) even at low concentrations. To determine if part of this barrier protective effect might be extracellular, we studied the effects of bovine serum albumin (BSA) on Lp of self-assembled basement membrane (Matrigel). Lp with tris(hydroxymethyl)aminomethane (Tris) buffer superfusate was stable at 1.77 +/- 0.22 x 10(-5) (SE) cm.s-1.cmH2O-1 over several hours. At 0.1 g/dl BSA, experimental/control (Tris) Lp fell to 83.1 +/- 6.0% (2P < 0.025), with decreases to 72.4 +/- 3.7% at 1 g/dl (2P < 0.005), 45.3 +/- 5.1% at 2.5 g/dl (2P < 0.001), and 45.0 +/- 4.8% at 4.0 g/dl (2P < 0.001). In separate experiments, BSA arginine groups were neutralized by 1,2-cyclohexanedione (CHD), and experimental/control Lp values were measured. At 2.5 g/dl, CHD-BSA depressed Lp to 54.4 +/- 4.8%, while unmodified BSA reduced Lp to 40.8 +/- 3.5% of Tris control (2P = 0.05). Finally, soluble arginine at three- and sixfold the arginine in BSA was added to BSA superfusate. For threefold, Lp rose to 120 +/- 8% of BSA level and for sixfold to 129 +/- 9% (2P < 0.05). We conclude that some part of the albumin protective effect is very likely due to consequences on extracellular matrix and that at least 18-22% of this effect is related to arginine groups on albumin when computed from Lp, and up to 34% when viscosity is taken into account. Membrane-saturable arginine-binding sites can be unbound with arginine, thus nullifying part of the barrier protective effect of BSA.

scholarly journals Hypothyroidism in rats does not lower mitochondrial ADP/O and H+/O ratios

1988 ◽  
Vol 250 (2) ◽  
pp. 477-484 ◽  
Author(s):  
R P Hafner ◽  
M D Brand
Keyword(s):  
Fatty Acid ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Adenylate Kinase ◽  
Bovine Serum ◽  
Mitochondrial Protein ◽  
Experimental Conditions ◽  
Low Concentrations ◽  
The Difference

We investigated reports that mitochondria isolated from hypothyroid rats have decreased ADP/O and H+/O ratios. We observed no decrease in the H+/O ratio in mitochondria from hypothyroid rats, in the presence of either 2% (w/v) fatty-acid-free bovine serum albumin or 100 nM free Ca2+. The ADP/O ratio in mitochondria isolated from hypothyroid rats in the presence of 2% fatty-acid-free bovine serum albumin was measured. Under normal experimental conditions we found no decrease in the ADP/O ratio, relative to that measured for littermate controls. At the low concentrations of mitochondrial protein used in the previously reported studies, the ADP/O ratio of mitochondria from hypothyroid rats was decreased, whereas that for control rats was only slightly decreased. The difference between the ADP/O ratios measured for mitochondria form hypothyroid rats and from control rats under these conditions was eliminated by inhibition of endogenous adenylate kinase. We suggest that the lowering of the apparent ADP/O ratio in mitochondria from hypothyroid rats at low concentrations of mitochondrial protein is an experimental artefact resulting from the breakdown of ADP to AMP.

Identification of the antitumoral drug emodin binding sites in bovine serum albumin by spectroscopic methods

2007 ◽  
Vol 1774 (11) ◽  
pp. 1359-1369 ◽  
Author(s):  
Paz Sevilla ◽  
José M. Rivas ◽  
Francisco García-Blanco ◽  
José V. García-Ramos ◽  
Santiago Sánchez-Cortés
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Binding Sites ◽  
Bovine Serum ◽  
Spectroscopic Methods
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