Papers by Keyword: Bovine Serum Albumin (BSA)

Abstract: A highly sensitive low-doped ZnO nanowire field effect transistor (NWFET) biosensor has been fabricated and measured. The low doped biosensor with NWFET transducer was used to sense charge of the following substances: lysozyme (LYSO), phosphate buffered saline (PBS), bovine serum albumin (BSA). It achieved maximum sensitivity of -543.2 % for the PBS-LYSO protein and 13,069 % for the PBS-BSA protein. These results were achieved because the electrical measurement and characterisation was focused on the charge effect of the LYSO and BSA acting on the ZnO nanowire subthreshold region. The nano-fabrication process is stable and reproducible. The high sensitivity of the ZnO NWFET biosensor can be exploited for selective analyte detection by functionalizing the nanowire surface with antibodies and/or other biomolecular probe molecules.

Abstract: 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 (K_sv) were calculated at different temperature. The binding site (n), apparent binding constant (K_a) and corresponding thermodynamic parameters △G^o, △H^o, △S^o were 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.

Abstract: The interaction between natural pheophorbide (a superior photosensitizer) and bovine serum albumin (BSA) in physiological condition is investigated by means of UV-Vis, fluorescence and synchronous fluorescence spectra so as to provide the basis for clinical use. Natural pheophorbide was isolated from silkworm excrement. BSA in pH 7.4 Tris buffer mixed with different concentration of pheophorbide was kept at certain temperature for 3 h or under illumination by laser at 630 nm for 20 min. UV-Vis absorption of BSA was enhanced and its fluorescence was quenched by pheophorbide. Illumination of laser at 630 nm intensified the quenching. The mechanism is deemed as mainly static quenching. The binding constants K_a at 300, 310, 320 K are separately 6.93×10¹²,7.40×10¹²,6.82×10¹² L/mol/s respectively. Number of binding sites n is 1; the binding distance R is 3.70 nm, and that suggests non-radiation energy transfer from BSA to pheophorbide. The thermodynamic parameters of the binding reaction are H=36.7 kJ/mol, S=213 J/mol/K, and G negative value, and indicates that hydrophobic force plays a predominant role in the process, and it is a spontaneous interaction. Synchronous fluorescence spectra show that pheophorbide mainly interacts with tryptophan residue of BSA and leads to the promotion of hydrophobic force. Pheophorbide can bind to serum protein and be transported in vivo, makes no destruction to molecular structure of serum protein, but causes its conformational alteration.

Abstract: The binding studies of imidacloprid to bovine serum albumin (BSA) were investigated by UV-Vis absorption spectrum, fluorescence spectrum and synchronous fluorescence spectrometry. Under the simulative physiological conditions, fluorescence data revealed the presence of a single class of binding site on BSA and the dynamic quenching constants () were 6.851×10⁴ L.mol^-1 and 5.813×10⁴ L.mol^-1 at 310 and 315 K, respectively, proving the mode of action of imidacloprid with BSA as a static quenching. In addition, according to the Vant Hoff equation, ΔG^θ <0 showed="" the="" combination="" of="" imidacloprid="" and="" bsa="" was="" a="" spontaneous="" process="" h="" sup="">θ <0 and="" s="" sup="">θ> 0, indicated an electrostatic interaction process. At the same time, synchronous fluorescence spectrum of BSA could tell us whether the conformation of BSA was changed by imidacloprid.

Abstract: In order to gain deeper insight into the interaction mechanism between bovine serum albumin (BSA) and polyethylene glycol (PEG), the present work applied elastic light scattering (ELS) spectroscopy to investigate the interaction between BSA and PEG, and explore the effects of concentration and molecular weight of PEG on the interaction at physiological pH. The results showed that the interaction force existed between linear PEG and spherical BSA molecules was mainly hydrogen bonding. In addition, the apparent binding constant of system was evaluated by model calculation.

Abstract: The interactions of bovine serum albumin (BSA) with phosphotungstic heteropoly acid (PW), silicon tungsten heteropoly acid (SiW) and silicon tungsten-cobalt acid (SiWCo) were studied by fluorescence spectroscopy and UV absorption spectroscopy at Tris buffer solution (pH = 7.40). It was found that the fluorescence quenching of PW, SiW and SiWCo with BSA was static and the binding constant, binding site and the thermodynamic parameters were calculated at 298 and 310K. In addition, the conformations of BSA impacted by PW, SiW and SiWCo were researched using synchronous fluorescence. The results showed that PW, SiW and SiWCo all could interact with BSA but they had not changed the conformation of BSA.

Abstract: The water-soluble conjugated polyelectrolyte, poly[3-(1′-propyloxy-3′-sodium sulfonate) thiophene] (PTH-n3-SO3Na), was prepared. The interaction between the PTH-n3-SO3Na and bovine serum albumin (BSA) was investigated using UV-vis spectroscopy. It was found that the PTH-n3-SO3Na could be used as biosensor to detect BSA.

Abstract: In this paper, we used bovine serum albumin and polymer as the blocking agents and investigated the effect of blocking agents on non-specific background of polystyrene microbead that used the human serum immunoassay.The results showed that the nonspecific background is lower by using polymer blocking agents. The best blocking condition was that microbeads were blocked by PVXT (0.5% polyvinyl alcohol PVA, 0.8% polyvinylpyrrolidone, 0.05% Tween-20, PBS phosphate buffer, pH7.0) for two hours at room temperature.

Abstract: Plumbagin (PLN) is isolated from Plumbago Zeylanica, an anticancer Traditional Chinese Medicine. The interaction between cytotoxic complex [Sm (PLN)3(H2O)2]H2O and bovine serum albumin (BSA) is investigated by fluorescence, synchronous fluorescence, and UV-vis spectra. It is observed that Sm(III) complex can reduce the fluorescence intensity of BSA by the way of static quenching.

Abstract: The binding reaction of Zn(II) complex [Zn(C₈H₁₀N)₂Cl₂] with bovine serum albumin(BSA) was studied by fluorescence spectroscopy under the simulative physiological conditions. The intrinsic fluorescence of BSA could be quenched by Zn(II) complex. The quenching mechanism was suggested as static quenching according to the Stern–Volmer equation. The binding constants K_b and the number of binding sites n were calculated. The Zn(II) complex exhibit good binding propensity to bovine serum albumin having relatively high binding constant values. The thermodynamic parameters indicate that the hydrogen bonds and van der Waals forces play a major role in BSA-Zn(II) complex association. The process of binding was spontaneous, in which Gibbs free energy change (Δ_G) was negative.