摘要
By using equilibrium dialysis, atomic absorption spectrometry, fluorescence titration and determination of fluorescence lifetime, it can be determined that each fibrinolytic principle(FP) molecule contains one Ca 2+ binding site and one Ca 2+ ion. The energy transfer between Tb 3+ and the Trp residue in FP was studied through fluorescence spectroscopy. Our studies show that the Ca 2+ ion in an FP molecule can be substituted by Tb 3+ ion. In FP molecule, the excition energy can be transfered from the Trp residue as an energy donor to Tb 3+ as an acceptor, substituted into FP and located near the Trp residue. The distance between Tb 3+ and the Trp residue, ～0 375 nm, was worked out with the experimental data and Forster theory.
By using equilibrium dialysis, atomic absorption spectrometry, fluorescence titration and determination of fluorescence lifetime, it can be determined that each fibrinolytic principle(FP) molecule contains one Ca 2+ binding site and one Ca 2+ ion. The energy transfer between Tb 3+ and the Trp residue in FP was studied through fluorescence spectroscopy. Our studies show that the Ca 2+ ion in an FP molecule can be substituted by Tb 3+ ion. In FP molecule, the excition energy can be transfered from the Trp residue as an energy donor to Tb 3+ as an acceptor, substituted into FP and located near the Trp residue. The distance between Tb 3+ and the Trp residue, ～0 375 nm, was worked out with the experimental data and Forster theory.
