The binding of Tb 3+ to chicken apoovotransferrin was studied by monitoring the fluorescent intensity of Tb 3+ at 549 nm. The conditional equilibrium constants for the complexation of Tb 3+ by chicken apoovotransferri...The binding of Tb 3+ to chicken apoovotransferrin was studied by monitoring the fluorescent intensity of Tb 3+ at 549 nm. The conditional equilibrium constants for the complexation of Tb 3+ by chicken apoovotransferrin in 0 1 mol/L hepes, at pH 7 4 and room temperature were measured. The successive macroscopic binding constants are lg K 1=9 08±0 12 and lg K 2=7 36±0 22. The molar fluorescence enhancement of Tb 3+ apoovotransferrin complex is (2 06±0 14)×10 4 mol -1 ·L. The fluorescence quenching experiment and the titration of N terminal monoferric ovotransferrin showed that Tb 3+ has a preference for being bound to the N terminal binding site of apoovotransferrin.展开更多
文摘The binding of Tb 3+ to chicken apoovotransferrin was studied by monitoring the fluorescent intensity of Tb 3+ at 549 nm. The conditional equilibrium constants for the complexation of Tb 3+ by chicken apoovotransferrin in 0 1 mol/L hepes, at pH 7 4 and room temperature were measured. The successive macroscopic binding constants are lg K 1=9 08±0 12 and lg K 2=7 36±0 22. The molar fluorescence enhancement of Tb 3+ apoovotransferrin complex is (2 06±0 14)×10 4 mol -1 ·L. The fluorescence quenching experiment and the titration of N terminal monoferric ovotransferrin showed that Tb 3+ has a preference for being bound to the N terminal binding site of apoovotransferrin.