<title>Time-resolved fluorescence study of interaction of the monoclonal anticoproporphyrin antibodies and (Pt-)coproporphyrin</title>

Mechanisms of ligand binding by monoclonal anti-coproporphyrin antibodies are studied by steady-state and time-resolved fluorescence spectroscopy by use of a picosecond laser system. The antibodies quench the coproporphyrin (CP) fluorescence, but the CP fluorescence spectra show a strong shift of maxima at high concentrations of antibodies (Ab) or their Fab fragment. This can be explained by a special type of Ab or Fab dimerization. Fluorescence decays of CP are measured at different concentrations of Ab and different pH values. The following deconvolution procedure based on the non-linear least squares method reveals a two- exponential character of the fluorescence decay. Data obtained by …