Bovine Serum Albumin

Reverse micelle extraction by using Sodium bis (2-ethylhexyl) Suffoccinate (AOT) of protein bovine serum albumin (BSA) and lysozyme was investigated in this research. Study of factors affecting the surfactant concentration and pH of aqueous for both forward and backward extraction process was performed in the research. The BSA concentrations were characterized by using the UV- spectrophotometer at wavelength, λ = 280 nm. The result indicated that the extraction percentage of lysozyme was higher than BSA in forward transfer for both parameters; however BSA demonstrated a better extraction performance in backward extraction process. The maximum lysozyme extracted in the forward extraction process was at 60 mM of surfactant concentration while for BSA was 100 mM since BSA is a bulky molecule and the size is larger than of lysozyme.

CONCLUSION: The results showed that losartan potassium can bind to bovine serum albumin by hydrogen bonding and Van der Waals forces. The primary binding for losartan potassium was located at site II in subdomain IIIA of BSA. The result observed by synchronous fluorescence and three- dimensional fluorescence spectra demonstrated that the presence of LP induced some micro environmental and conformational changes of BSA molecules. The results are of great importance in pharmacy, pharmacology and biochemistry, and are expected to provide important insight into the interactions of the physiologically important protein BSA with drugs.

The interaction between biomacromolecules, especially between plasma proteins and drugs, has been an interesting research field in life sciences, chemistry, and clinical medicine (Lu et al., 2010). Drug-albumin complexes may be considered as models for gaining fundamental insights into drug-protein interactions. Serum albumin is a major soluble protein constituent of the circulatory system and has many physiological functions such as acting as a plasma carrier by nonspecifically binding to several hydrophobic steroid hormones and as a transport protein for hemin and fatty acids (Zunszain et al., 2003). Albumins are characterized by a low content of tryptophan and methionine and a high content of cystine and charged amino acids (Brown,, 2003; Patterson and Geller, 1977; Hirayama et al., 1990). Bovine serum albumin (BSA), its molecular structure shown in Figure (1) which is an example of a mammalian albumin, has been studied extensively because of its stability, neutrality in many biochemical reactions, and low cost (Peters, 1985; Tarushi et al., 2010). Brown elucidated the 607 amino acid residue, primary structure of BSA in 1975, twenty one of which are tyrosine (Tyr) residues and two of which are tryptophan (Trp) *Corresponding author: Abu Teir, M.M.

Hydroxycinnamic acids (HCAs) possess numer- ous biological effects including antioxidant, an- tiallergic, antimicrobial, and immunomodulatory activities and due to these properties are widely used in folk medicine. Nevertheless, they can interact with protein molecules and cause some structural and functional changes. The possib- ility of HCAs binding to bovine serum albumin (BSA) under physiological conditions was inve- stigated by the UV-VIS absorption spectroscopy and fluorescence quenching method. Apart from rosmarinic acid, all tested HCAs quenched tryptophan fluorescence of BSA in the studied range of concentrations (0-20 µM) mainly by static quenching mechanism (formation of non- fluorescent HCA-BSA complexes). The binding constants, number of binding sites and free en- ergy changes were determined. The binding affinities of HCAs were ranked in the order: chlorogenic acid > sinapic acid ≥ caffeic acid > ferulic acid > o-coumaric acid > p-coumaric acid ≥ m-coumaric acid, which was confirmed by spectral overlaps of BSA emission spectrum with absorption spectrum of HCA. All free en- ergy changes possessed negative sign indicat- ing the spontaneity of HCA-BSA interaction. Keywords: Bovine Serum Albumin; Hydroxycinnamic Acid; Fluorescence Quenching; Protein-Ligand Binding

Serum albumins are the most abundant carrier pro- teins of blood plasma that promote the transportation and disposition of exogenous and endogenous materi- als in blood. They are able to bind with different bio- logically active compounds (drugs, fatty acids, steroids, dyes etc) in the body [18-20]. The structure of BSA is homologous to HSA (human serum albumin) and con- sists of three linearly arranged domains (I-III) that are composed of two subdomains (A and B) [21-23]. There are two tryptophans (Trp 134 and Trp 213) in BSA, of which Trp 134 is located on the surface of the mole- cule and Trp 213 resides in the hydrophobic pocket similar to Trp 214 in HSA [24,25]. Like other serum albumins bovine serum albumin (BSA) possesses a wide range of physiological functions associated with the binding, transport and distribution of biologically active compounds. The binding affinity to serum al- bumins also influences the effectiveness of the drugs at the active site. Thus the study of the interactions of small drug molecules with serum albumins provides a good insight into an understanding of the recognition pattern under physiological conditions [26]. In this regard, BSA is extensively used because of its intrinsic structural similarity with HSA [27-30].

From the above results it was observed that all the formulations showed biphasic release. All the formulations showed about 20% of drug release quickly from cefazolin loaded bovine serum albumin nanoparticles with the first 0.5 hour and then followed by relatively slow release rate. This initial burst release was caused by the drug dispersed close to the nanoparticle surface. This part of adsorbed drug could be easily desorbed from the outer layer and diffused out (Li FQ et al., 2008). The drug incorporated into the inner core of the protein matrix contributed for slow release phase (Wilson B et al., 2012) & (Irache J.M et al., 2001). The albumin matrix of the nanoparticle is stables during invitro drug release, it was reasonable owing to the insolubility of denatured bovine serum albumin (Fude cui et al., 2007)

Nevirapine is a non-nucleoside reverse transcriptase inhibitor used for the treatment of Human Immunodeficiency Virus Type-1 infection and AIDS. A systematic interaction between nevirapine and bovine serum albumin (BSA) has been investigated by UV-Vis absorption, infra-red (IR) spectra, fluorescence, circular dichroism (CD), cyclic voltammetry (CV), and nuclear magnetic resonance (NMR) spectroscopy. UV-Vis absorption and fluorescence quenching is attributed to the formation of nevirapine-BSA complex. The fluorescence analysis indicates the quenching of BSA by nevirapine occurs through static procedure. Synchronous fluorescence, CD, and IR spectra revealed the conformation and microenvironment of BSA were altered by interaction with nevirapine. NMR spectroscopic results suggested hydrogen bonding and hydrophobic interactions played an important role in nevirapine-BSA complex formation. Cyclic voltammetry (CV) proved the interaction of nevirapine with BSA forming an electrochemically inactive complex.

CoCrMo high carbon gas atomized powders (ASTM75, ~ 60% Co, 27% Cr, 6% Mo) was purchased from Sandvik Osprey. The starting powder had a particle size of around 16 μm. Bovine Serum Albumin (BSA), heat shock, pH 7.0 was acquired from Fisher Scientific, and used during milling as a process control agent. The solution used was composed of 0.4 g of BSA diluted in 10 mL of deionized water. The powder was ball milled for 150 min in a high energy Spex 8000M mill using zirconia ceramic vials and balls. Before milling, the vial was filled with an inert gas (Argon) to avoid atmospheric contamination. A ball-to-powder weight ratio of 3:2 was used. After collection, samples were centrifuged in a Heraeus Megafuge for 10 min, at 25 °C and a centrifugal force of 8000 G. This procedure removes the excess BSA and coarse particles (>200nm), maintaining most of the fine particles in dispersion (20mg/mL). Co 3 O 4 , Cr 2 O 3 , Mo nanoparticles (which exhibit MoO 2 on the

The interaction between benzylidene piperidone (BzP) and bovine serum albumin (BSA) was investigated by spectroscopic techniques. It was observed that BzP has a strong ability to quench the intrinsic fluorescence of BSA through static quenching. The binding constant ‘K’ and number of binding sites ‘n’ were calculated, and Gibbs free energy [ ∆ G 0 ] change was found to be negative. The negative ∆ G 0 values confirmed that the binding process is spontaneous. The conformation changes of BSA investigated by synchronous, and circular dichroism spectra revealed the changes in the secondary structure of BSA upon interaction with BzP. Synchronous fluorescence spectra showed a change from red to blue shift which is an indication of increasing hydrophobicity.

Abstract: Bovine serum albumin (BSA) is highly water soluble and binds drugs or inorganic substances noncovalently for their effective delivery to various affected areas of the body. Due to the well-defined structure of the protein, containing charged amino acids, albumin nanoparticles (NPs) may allow electrostatic adsorption of negatively or positively charged molecules, such that substantial amounts of drug can be incorporated within the particle, due to different albumin-binding sites. During the synthesis procedure, pH changes significantly. This variation modifies the net charge on the surface of the protein, varying the size and behavior of NPs as the drug delivery system. In this study, the synthesis of BSA NPs, by a desolvation process, was studied with salicylic acid (SA) as the active agent. SA and salicylates are components of various plants and have been used for medication with anti-inflammatory, antibacterial, and antifungal properties. However, when administered orally to adults (usual dose provided by the manufacturer), there is 50% decomposition of salicylates. Thus, there has been a search for some time to develop new systems to improve the bioavailability of SA and salicylates in the human body. Taking this into account, during synthesis, the pH was varied (5.4, 7.4, and 9) to evaluate its influence on the size and release of SA of the formed NPs. The samples were analyzed using field-emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared, zeta potential, and dynamic light scattering. Through fluorescence, it was possible to analyze the release of SA in vitro in phosphate-buffered saline solution. The results of chemical morphology characterization and in vitro release studies indicated the potential use of these NPs as drug carriers in biological systems requiring a fast release of SA.

Binding of pesticides to serum albumin significantly influence their absorption, metabolism, distribution and excretion. In the present study, interactions of acephate, glyphosate, monocrotophos and phorate with bovine serum albumin were explored employing the UV/Vis and Fourier-transform infrared spectroscopy methods. The observed values of binding constant for titled pesticides were phorate (1.85×107 M -1 )>acephate

The interaction of losartan potassium (LP) with bovine serum albumin (BSA) was studied by fluorescence quenching in combination with UV–Vis spectroscopic method under near physiological conditions. The fluorescence quenching rate constants and binding constants for BSA–LP system were determined at different temperatures. The fluorescence quenching of BSA by LP is due to static quenching and energy transfer. The results of thermodynamic parameters, ∆ H ( ‒ 134.3 kJ mol ‒ 1 ), ∆ S ( ‒ 368 J mol ‒ 1 K ‒ 1 ) and ∆ G ( ‒ 24.52 to ‒ 20.83 kJ mol ‒ 1 ), indicated that van der Waals interaction and hydrogen bonding played a major role for LP–BSA association. The competitive experiments demonstrated that the primary binding site of LP on BSA was located at site II in sub-domain IIIA of BSA. The distance between LP and a tryptophane unit was estimated to be 3.183 nm based on the Förster resonance energy transfer theory. The binding constant (K a ) of BSA–LP at 298K was 1.932×10 4 L mol

11. Wani TA, Bakheit AH, Al-Majed AA, Bhat MA, Zargar S. Study of the interactions of bovine serum albumin with the new anti-inflammatory agent 4-(1, 3-dioxo-1, 3-dihydro-2H-isoindol-2-yl)-N′-([4-ethoxy- phenyl] methylidene) benzohydrazide using a multi-spectroscopic approach and molecular docking. Molecules. 2017;22(8):1258. 12. Steinhardt J, Krijn J, Leidy JG. Differences between bovine and human

Semiconductor nanoparticles (quantum dots) are promising fluorescent markers, but it is very little known about interaction of quantum dots with biological molecules. In this study, interaction of CdTe quantum dots coated with thioglycolic acid (TGA) with bovine serum albumin was investigated. Steady state spectroscopy, atomic force microscopy, electron microscopy and dynamic light scattering methods were used. It was explored how bovine serum albumin affects stability and spectral properties of quantum dots in aqueous media. CdTe – TGA quantum dots in aqueous solution appeared to be not stable and precipitated. Interaction with bovine serum albumin significantly enhanced stability and photoluminescence quantum yield of quantum dots and prevented quantum dots from aggregating.

After the addition of bovine serum albumin (BSA) into colchicine solution, the oxidative peak currents decreased with the positively shift of the peak potential and no appearance of new peak. This electrochemical method was further applied to the determination of BSA in pharmaceutical formulations. The interaction between colchicine and BSA was investigated by electrochemical and spectroscopic methods. The binding constant and the number of binding sites of the interaction system were calculated by fluorescence spectroscopy.

Gelatin (Gel) and chitosan (CTS) have several biomedical applications be- cause of their biodegradability and biocompatibility. Crosslinking of Gel and Gel/CTS systems was evaluated using N-acetyl-D-glucosamine (GlcNAc) formed into sponges by lyophilization. The prepared sponges were used to study the adsorption and desorption of fluorescein isothiocyanate (FITC) la- beled bovine serum albumin (BSA) as a model instead of a growth factor. The effect of FITC-BSA concentration and temperature on the adsorption beha- vior of Gel/CTS sponges was investigated. The Langmuir adsorption isotherm model was used on the basis of the assumption that monolayer adsorption occurs on the surface; the results fit with the experiment data. The adsorption constants were 5.77 and 9.68 mL/mg for Gel and Gel/CTS sponges, respec- tively. The adsorption thermodynamic constants were found; adsorption onto sponges was an exothermic reaction. In particular, Gibbs free energy (ΔG) ex- hibited negative values in the range of 283 - 343 K for both Gel and Gel/CTS sponges, demonstrating the spontaneous nature of adsorption reaction. In ad- dition, desorption behavior was evaluated for different concentrations and pH values of the FITC-BSA solution. The high adsorbed amounts of FITC-BSA on sponge resulted in high desorbed amounts in sponge, up to 55% from 3.5 mg/mL adsorbed concentration (around 1.5 mg from 3 mg adsorb amount). Desorption decreased following the buffer solution pH decrease, from 7.4 to 4 and 2 in Gel and Gel/CTS sponges, respectively. Based on the results of this preliminary study, these composite sponges could have significant application in biomedical materials.

The objective of the paper is to determine the effect of β-cyclodextrin complexation on the interaction of the popular drug, Atorvastatin to bovine serum albumin. Fluorescence and 2D Rotating-frame Overhauser effect spectroscopic techniques are used to determine the stoichiometry, the binding contant, and the mode of binding of Atorvastatin to β-cyclodextrin. The role of the Atorvastatin-β-cyclodextrin complexation in modulating the binding strength of the drug to the model carrier protein bovine serum albumin is studied using absorption and fluorescence spectral measurements and molecular docking. Atorvastatin shows a fluorescence enhancement on comlplex formation with β-cyclodextrin. The results of the binding of the drug to bovine serum albumin in free- and β-cyclodextrin-bound forms. The magnitude of quenching of the fluorescence of bovine serum albumin due to drug binding, an d the Fӧrster energy transfer efficiency between the protein and the drug are decreased in the presence of β-cyclodextrin. The binding constant value of the drug–protein binding in the absence and presence of β-cyclodextrin are 5.36 × 10 4 M -1 to 2.32 × 10 4 M -1 , respectively. Atorvastatin forms a 1:2 inclusion complex with cyclodextrin. The isopropyl substituent in the pyrrole ring of Atorvastatin binds to β-cyclodextrin. Cyclodextrin modulated the binding of drug to the serum albumin, i.e., the cyclodextrin complex of Atorvastatin binds to bovine serum albumin with diminished binding strength. Nevertheless, the exposed part of the drug is found to be sufficient for interaction with the same binding pocket as the free drug binds to.

Abstract. Flat sheet dialysis membranes were casted using phase inversion method, using cellulose acetate as the polymer and acetic acid as the solvent. Modification agents such as polyethylene glycol 400 (PEG 400) and non-solvent swelling agent, i.e. distillated water were added. Three different formulations were used, and the performances of the obtained membranes were tested for protein separation using a 2 mg/mL bovine serum albumin (BSA) solution. It was found that the membrane obtained from the formulation consisting of 20%wt cellulose acetate, 60%wt acetic acid, 10%wt PEG 400 and 10%wt distillated water gives a BSA rejection rate as high as 96.19%, which seems to be comparable with the commercial cellulose acetate dialysis membranes. However, testing the same membranes for separation of sucrose solution does not give satisfactory result as indicated by the low rejection rates of 50%.

Background: This study aimed to generate targeted folic acid-conjugated, doxorubicin-loaded, magnetic iron oxide bovine serum albumin nanospheres (FA-DOX-BSA MNPs) that lower the side effects and improve the therapeutic effect of antitumor drugs when combined with hyper- thermia and targeting therapy. A new nanodrug using magnetic nanospheres for heating and addition of the folate receptor with cancer cell specificity was prepared. The characteristics of these nanospheres and their antitumor effects in nasopharyngeal carcinoma were explored. Methods: FA-DOX-BSA MNPs comprising encapsulated magnetic iron oxide nanopar- ticles were prepared using a desolvation cross-linking method. Activated folic acid (N- hydroxysuccinimide ester of folic acid) was conjugated to the surface of albumin nanospheres via amino groups.

In this paper, the interaction of lomefloxacin (LMF) and/or cefazolin (CFZ) with bovine serum albumin (BSA) was studied by fluorescence quenching in combination with UV-vis spectroscopic method under simulative physiological conditions. The fluorescence quenching constants, binding distance, and binding constants for BSA–LMX and/or CFZ systems were determined. The fluorescence quenching of BSA by addition of LMF and/or CFZ is due to static quenching and energy transfer. The ratio of binding constants (K a ) for BSA–LMF to BSA–CFZ equals to 22.41. In