An optical biosensor with a stirred cuvette has been used to monitor the interaction of immobilized wheat germ agglutinin （WGA） with two water-soluble cationic porphyrins, The association constants （Ka） of the fre...An optical biosensor with a stirred cuvette has been used to monitor the interaction of immobilized wheat germ agglutinin （WGA） with two water-soluble cationic porphyrins, The association constants （Ka） of the free base porphyrin and its Zn（Ⅱ） complex form were 2. 66 and 27.31 × 10^5 l,/mol at 20 ℃ respectively. The interactions of the free base porphyrin were further investigated at temperatures between 15 ℃ and 37 ℃, The thermodynamics parameters, changes in free energy, enthalpy and entropy, were -31.23, 22.92, 54.15 ld/mol respectively. The heat capacity change was -355.53 J · mol^-1·K^-1 The binding was driven by entropic contribution, and showed strong enthalpy-entropy compensation. It was governed primarily by hydrophobic forces.展开更多
An optical biosensor with a stirred cuvette has been used to monitor the interaction between immobilized human serum albumin （HSA） and three water-soluble cationic porphyrins. The binding constants at 25℃ obtained ...An optical biosensor with a stirred cuvette has been used to monitor the interaction between immobilized human serum albumin （HSA） and three water-soluble cationic porphyrins. The binding constants at 25℃ obtained from biosensor analysis were compared with those from fluorescence spectroscopy. The interactions were further investigated at temperatures from 15℃ to 30℃. The thermodynamics parameters, changes of free energy （△G）, enthalpy （△H） and entropy （△S）, were evaluated from equilibrium data. It appeared that the binding process was governed primarily by electrostatic forces.展开更多
文摘An optical biosensor with a stirred cuvette has been used to monitor the interaction of immobilized wheat germ agglutinin （WGA） with two water-soluble cationic porphyrins, The association constants （Ka） of the free base porphyrin and its Zn（Ⅱ） complex form were 2. 66 and 27.31 × 10^5 l,/mol at 20 ℃ respectively. The interactions of the free base porphyrin were further investigated at temperatures between 15 ℃ and 37 ℃, The thermodynamics parameters, changes in free energy, enthalpy and entropy, were -31.23, 22.92, 54.15 ld/mol respectively. The heat capacity change was -355.53 J · mol^-1·K^-1 The binding was driven by entropic contribution, and showed strong enthalpy-entropy compensation. It was governed primarily by hydrophobic forces.
基金Project supported by the National Natural Science Foundation of China （No. 30370366）.
文摘An optical biosensor with a stirred cuvette has been used to monitor the interaction between immobilized human serum albumin （HSA） and three water-soluble cationic porphyrins. The binding constants at 25℃ obtained from biosensor analysis were compared with those from fluorescence spectroscopy. The interactions were further investigated at temperatures from 15℃ to 30℃. The thermodynamics parameters, changes of free energy （△G）, enthalpy （△H） and entropy （△S）, were evaluated from equilibrium data. It appeared that the binding process was governed primarily by electrostatic forces.
