The interaction between silicotungstic heteropolyacid and bovine hemoglobin (BHb) was investigated using fluorescence and UV-Vis. The experimental results show that the fluorescence quenching of BHb by silicotungstic ...The interaction between silicotungstic heteropolyacid and bovine hemoglobin (BHb) was investigated using fluorescence and UV-Vis. The experimental results show that the fluorescence quenching of BHb by silicotungstic heteropolyacid is a result of the formation of SiW-BHb complex; and the quenching mechanism is mainly static quenching. The binding site number n, apparent binding constant KA and corresponding thermodynamic parameters were measured at different temperatures. The process of binding SiW molecule on BHb was a spontaneous molecular interaction procedure in which entropy increased and Gibbs free energy decreased. Electrostatic interaction plays a major role in stabilizing the complex. The effect of silicotungstic heteropolyacid on the conformation of BHb was analyzed using synchronous fluorescence spectroscopy.展开更多
The interaction of Methylthymol Blue(MTB)-Zinc! compound and Alizarin Red S(ARS)-Aluminum" compound with Bovine serum albumin (BSA) was investigated by UV-Vis spectrophotometric method in acidic buffer solution. ...The interaction of Methylthymol Blue(MTB)-Zinc! compound and Alizarin Red S(ARS)-Aluminum" compound with Bovine serum albumin (BSA) was investigated by UV-Vis spectrophotometric method in acidic buffer solution. MTB-Zn!-BSA was a blue color compound, which possesses maximum absorption at 613 nm with 172 nm, 174 nm and 18 nm of red shift compared to the MTB, MTB-BSA and MTB-Zn! complexes respectively. Dual wavelength substantial amount ratio method, balance dialysis substantial amount ratio method and unity wavelength substantial amount ratio method were compared. The following results were obtained: the apparent molar absorptivity of MTB-Zn! with BSA was ε=2.20×104 L·mol-1·cm-1. Conditional proportion were defined, nMTB∶nZn!∶nBSA=2∶2∶1; condition combination constant, K=2.07×1010. Combination proportion were defined, nARS∶nAl"∶ nBSA=6∶4∶1. Condition equilibrium constant of reaction of ARS-Al" with BSA was K=8.80×108. The apparent mo- lar absorptivity of ε=2.65×104 L·mol-·1cm-1. It is suggested that combination between BSA and MTB-Zn" is due to coordination force. That combination between BSA and ARS-Al" is due to the coordination bond and electro- static force.展开更多
文摘The interaction between silicotungstic heteropolyacid and bovine hemoglobin (BHb) was investigated using fluorescence and UV-Vis. The experimental results show that the fluorescence quenching of BHb by silicotungstic heteropolyacid is a result of the formation of SiW-BHb complex; and the quenching mechanism is mainly static quenching. The binding site number n, apparent binding constant KA and corresponding thermodynamic parameters were measured at different temperatures. The process of binding SiW molecule on BHb was a spontaneous molecular interaction procedure in which entropy increased and Gibbs free energy decreased. Electrostatic interaction plays a major role in stabilizing the complex. The effect of silicotungstic heteropolyacid on the conformation of BHb was analyzed using synchronous fluorescence spectroscopy.
文摘The interaction of Methylthymol Blue(MTB)-Zinc! compound and Alizarin Red S(ARS)-Aluminum" compound with Bovine serum albumin (BSA) was investigated by UV-Vis spectrophotometric method in acidic buffer solution. MTB-Zn!-BSA was a blue color compound, which possesses maximum absorption at 613 nm with 172 nm, 174 nm and 18 nm of red shift compared to the MTB, MTB-BSA and MTB-Zn! complexes respectively. Dual wavelength substantial amount ratio method, balance dialysis substantial amount ratio method and unity wavelength substantial amount ratio method were compared. The following results were obtained: the apparent molar absorptivity of MTB-Zn! with BSA was ε=2.20×104 L·mol-1·cm-1. Conditional proportion were defined, nMTB∶nZn!∶nBSA=2∶2∶1; condition combination constant, K=2.07×1010. Combination proportion were defined, nARS∶nAl"∶ nBSA=6∶4∶1. Condition equilibrium constant of reaction of ARS-Al" with BSA was K=8.80×108. The apparent mo- lar absorptivity of ε=2.65×104 L·mol-·1cm-1. It is suggested that combination between BSA and MTB-Zn" is due to coordination force. That combination between BSA and ARS-Al" is due to the coordination bond and electro- static force.
