In this paper, the new carbon nanotube modified glassy carbon electrode (F-CNTs/GCE) was prepared to establish a new method for studying the molecular interaction mechanism between baicalin metal complexes (BMC) and bovine serum album (BSA), and the principle of this method was discussed deeply. Under the physiological condition, the thermodynamics and kinetics properties of interaction between BMC and BSA were studied by cyclic voltammetry (CV) to inference their molecular effective mechanism. The results show that the presence of F-CNTs can accelerate the electron transfer, and better response signal was showed in the BMC/BMC-BSA system. The detection of interaction of BMC-BSA used new method show that BMC-BSA generates stable thermodynamically non-covalent compounds, and the obtained average binding sites of BMC-BSA were 1.7; the number of electron transfer in BMC/BMC-BSA reaction process was 2, and non electroactive supramolecular compounds of BMC-BSA were generated by this interacting reaction. The relevant research work provides a new way to study the molecular mechanism for the interaction of drugs with protein, and with a certain reference value for discussion on the non covalent interactions.
Animals ; Cattle ; Coordination Complexes ; chemistry ; Electrodes ; Flavonoids ; chemistry ; Kinetics ; Nanotubes, Carbon ; Serum Albumin, Bovine ; chemistry ; Thermodynamics

Cell adhesion to material surface plays an important role in regulating cell function such as proliferation and differentiation. Surface patterning provides a useful method to control cell spatial distribution and adhesion to substance. Here microcontact printing and microfluidic channels were introduced to pattern MC3T3 E1 osteoblasts on silicon substance. Dichlordimethylsilane (DMS) was used in microcontact printing to generate the alternating domains of DMS and non-DMS, and cells preferentially adhered to the non-DMS and hydrophilic region. On the patterned surfaces generated from collagen and albumin solutions with microfluidic channels, cells preferentially localized in the collagen-coated region. The results also showed that micropatterning could be a useful method to study the effect of surface chemistry on cell adhesion and other functions.
Cell Adhesion ; Cells, Cultured ; Collagen ; chemistry ; Dimethylpolysiloxanes ; chemistry ; Osteoblasts ; physiology ; Serum Albumin, Bovine ; chemistry ; Surface Properties

Ultrafine iron oxide nanoparticles were prepared in aqueous solution using chemical coprecipitation method. Adsorption of bovine serum albumin (BSA) on magnetic particles was studied in the presence of silane coupling KH550. Characterizations of magnetic particles were carried out by X-ray diffraction, Transmission electron microscopy, Fourier transform infrared spectrometer and vibrating-sample magnetometer. The experimental results showed that magnetic nanoparticles were well dispersed with a small decrease of the magnetic saturation after modification. Magnetic nanoparticles wrapped in KH550 were favorable to the adsorption of BSA while the capability of hydrophile increased consequently, which could be used for target carrier in biomedicine.
Animals ; Cattle ; Ferrosoferric Oxide ; chemistry ; Magnetics ; Metal Nanoparticles ; chemistry ; Serum Albumin, Bovine ; chemistry

OBJECTIVE: To explore the interaction between cefdinir (CE) and bovine serum albumin (BSA) by fluorescence and ultraviolet-visible absorption spectrometry.
 METHODS: Under the optimal conditions, the interaction between CE and BSA was investigated by fluorescence and ultraviolet-visible absorption spectrometry.
 RESULTS: CE could quench (static quenching) the intrinsic fluorescence of BSA by forming the CE-BSA complex. The main binding forces were considered as hydrogen bonds and Van der Waals forces based on the calculated values of the thermodynamic parameter. The process of binding was spontaneous because Gibbs free energy change was negative. The primary binding site for CE was located at sub-domain II of BSA. The values of Hill's coefficients were less than 1, indicating a negative cooperative effect. Synchronous fluorescence spectra showed that the conjugation reaction between CE and BSA did not affect the conformation of BSA, and the binding site was close to the tyrosine residue.
 CONCLUSION This test provides a theoretical basis for revealing the pharmacokinetic issue and the development for new drugs.
Binding Sites ; Cefdinir ; Cephalosporins ; chemistry ; Serum Albumin, Bovine ; chemistry ; Spectrophotometry, Ultraviolet ; Thermodynamics

OBJECTIVETo observe the effects of different cell lysis buffers on protein quantification with Bradford method and bicinchoninic acid (BCA) method.

METHODSBradford method and BCA method were used to determine the concentration of bovine serum albumin (BSA) in different solutions (distilled water, cell lysis buffer used in two-dimensional differential in-gel electrophoresis and three kinds of cell lysis buffers used in conventional two dimensional gel electrophoresis), as well as the protein concentrations of cell lysates using these different lysis buffers. Bradford method was also applied to determine the protein concentrations of samples with repeated freeze thaw cycle, in different colorimetric cylinders, or using different standard curves from different periods.

RESULTThe protein measurements increased for 1.2 to 2 fold when different cell lysis buffers were used in Bradford method, but the measurements increased with the increased concentration of BSA (r=0.989 approximately 0.996, P<0.05). For BCA, measurement reading increased about thousands times higher, even overflowed the limits of machine. Protein measurements didn't change significantly, only showed a declined trend after repeated freeze thaw cycle, while no significant changes were found using different colorimetric cylinders or standard curves from different periods.

CONCLUSIONBradford method may be the choice of the protein quantification in proteomics. However, optimization is required for specific experimental conditions.

Buffers ; Cells ; Chemistry Techniques, Analytical ; methods ; Proteins ; analysis ; Serum Albumin, Bovine ; analysis ; Spectrophotometry, Ultraviolet

A fluorescence method is found for determination of bovine serum albumin (BSA). The method is based on the interaction of fluorescein with BSA to form a complex in Tris-HCl buffer of pH 2.2. The complex exitation wavelength is 467 nm, the emission wavelength is 515 nm. The linear measurement rang is between 1.8-500 mg/L for BSA, F = 26.776 C + 2.8082, r = 0.9999. This method is sensitive,steady,and low cost for determination of BSA.
Animals ; Cattle ; Drug Interactions ; Fluorescein ; chemistry ; Serum Albumin, Bovine ; analysis ; Spectrometry, Fluorescence ; methods

OBJECTIVETo establish a direct and fast method separating calcium levofolinate and calcium dextrofolinate in a bovine serum albumin stationary phase chiral column.

METHODSUsing EC150/4 RESOLVOSIL BSA-7(150 mm x 4 mm) chiral separation column, with 0.20 mol/L, pH=5.0 phosphate buffer as mobile phase HPLC method was performed to separate calcium folinate enantiomers.

RESULTThe capacity factor and resolution of the two calcium folinate enantiomers were greatly affected by mobile phase buffer concentration,pH and the column temperature. And the retention time of calcium levofolinate and calcium dextrofolinate were 18.5 min and 22.6 min, respectively. The resolution, R(s)=1.49.

CONCLUSIONCalcium folinate enantiomers are separated successfully using this method.

Chromatography, High Pressure Liquid ; Hydrogen-Ion Concentration ; Leucovorin ; chemistry ; metabolism ; Serum Albumin, Bovine ; metabolism ; Stereoisomerism

OBJECTIVETo study the conjugation reaction characteristics of caffeic acid micromolecule cistanoside F and bovine serum albumin.

METHODThe interaction between bovine serum albumin (BSA) and cistanoside F that was separated from Callicarpa plant for the first time and abbreviated CF was detected by fluorescence (FS), UV-vis absorbance and circular dichroism (CD) under simulative physiological conditions.

RESULTCF-BSA's static apparent binding constant (K(a)), number of binding sites (n), efficiency of energy transfer (E), spatial distance (r), thermodynamic parameters deltaG, deltaH and deltaS and changes in alpha-helical structure content in BSA before and after CF's effect were calculated to define the binding site of CF in BSA and analyze the impact of several common metal ions on the interaction of CF and BSA.

CONCLUSIONGround state compounds formed by CF and BSA could cause intrinsic fluorescence quenching. Their binding constant K(a) of cistanoside F with BSA was 4.36 x 10(4) L x mol at 25 degrees C, the number of binding site n was 1, and the spatial distance r was 3.09 nm. The results indicated that the hydrogen bond played a major role in cistanoside F-BSA association. The displacement experiments confirmed that cistanoside F can bind to site I of BSA. In addition, the binding constant of cistanoside F with BSA was enhanced after the addition of some common metal ions Mg2+, Fe3+, Cu2+ and Zn2+. The intrinsic fluorescence of BSA was quenched by cistanoside F via forming cistanoside F-BSA complex and non-radiation energy transfer. CD spectra showed that the binding of cistanoside F with BSA induced conformational changes in BSA.

Animals ; Caffeic Acids ; chemistry ; Catechols ; chemistry ; Cattle ; Circular Dichroism ; Glycosides ; chemistry ; Serum Albumin, Bovine ; chemistry ; Spectrometry, Fluorescence ; Spectrophotometry, Ultraviolet ; Thermodynamics

The evaluation of the adsorption of methylene blue (MB) in plasma by sulfonated polyethersulfone (SPES) adsorbent column was carried out in this study. The results indicated the adsorption of MB by SPES adsorbent column was more efficient than that by polyethersulfone (PES). In addition, the changes of the concentration of BSA solution passing through adsorbent column along with the time and the biochemical indices of plasma before and after adsorption treatment were also investigated. The results showed that the adsorption amount of BSA by PES adsorbent column was larger than that by SPES, and the biochemical parameters such as total protein, albumin, glucose, triglyceride and total cholesterol in plasma varied slightly before and after passing through the column, which were still within the clinical indices.
Adsorption ; Humans ; Methylene Blue ; isolation & purification ; Plasma ; chemistry ; Polymers ; chemical synthesis ; chemistry ; Serum Albumin, Bovine ; chemistry ; Sulfones ; chemical synthesis ; chemistry

AIMTo study the interaction mechanism of bovine serum albumin (BSA) with luteolin and apigenin.

METHODSFluorescence quenching method and non-radioactive energy transfer theory were used.

RESULTSThe binding constants at different temperature were determined and the quenching mechanism of them were suggested as static quenching. The transfer efficiency of energy and distance between BSA and luteolin or apigenin were investigated according to the mechanism of the Förster energy transference.

CONCLUSIONThe interaction between them seems to be strong and the binding force were mainly hydrophobic force. B(3')-OH,B(4')-OH strengthened the interaction of flavonoids and BSA.

Apigenin ; chemistry ; Energy Transfer ; Luteolin ; chemistry ; Protein Binding ; Serum Albumin, Bovine ; chemistry ; Spectrometry, Fluorescence ; Spectrophotometry, Ultraviolet ; Thermodynamics