Detection of Individual p53-Autoantibodies by Using Quenched Peptide-Based Molecular Probes


  • The authors thank K.H. Drexhage for the oxazine derivative MR121, and the Volkswagen-Stiftung, the Forschungsschwerpunktprogramm of the Land Baden-Wuerttemberg, and the Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie for financial support.


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Single-molecule spectroscopy for cancer diagnostics: Short dye-labeled peptide epitopes derived from human p53 show strong fluorescence quenching owing to efficient electron transfer from a tryptophan residue to the fluorophore (1, see picture). The specific recognition of the peptide epitope by the antibody induces a change in the conformation which is accompanied by a strong increase in fluorescence intensity. The fluorescing antibody–peptide complex can be detected at the single-molecule level even in slightly diluted serum samples by using confocal fluorescence microscopy.