title: Label-free detection of protein interactions using deep UV fluorescence lifetime microscopy.
abstract: We present a label-free detection of protein interaction between beta-galactosidase from Escherichia coli (Ecbeta-Gal) and monoclonal anti-Ecbeta-Gal using deep UV laser-based fluorescence lifetime microscopy. The native fluorescence from intrinsic tryptophan emission was observed after one-photon excitation at 266 nm. Applying the time-correlated single-photon counting (TCSPC) method, we investigated the mean fluorescence lifetime and lifetime distributions from tryptophan residues in Ecbeta-Gal protein, monoclonal anti-Ecbeta-Gal, and corresponding complex. The results demonstrate that deep UV laser-based fluorescence lifetime microscopy is useful for sensitive identification of biological macromolecules interaction using intrinsic fluorescence.
authors.affiliation: Physikalisch-Chemisches Institut der Universität Zurich, CH-8057 Zurich, Switzerland.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Stefan
authors.initials: S
authors.lastname: Seeger
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000378:metabolism; D000936:Antigen-Antibody Complex / Q000737:chemistry / Q000378:metabolism; D000937:Antigen-Antibody Reactions; D004926:Escherichia coli / Q000201:enzymology; D066298:In Vitro Techniques; D051379:Mice; D008856:Microscopy, Fluorescence / Q000379:methods*; D011485:Protein Binding; D025941:Protein Interaction Mapping / Q000379:methods*; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism*; D014364:Tryptophan / Q000031:analogs & derivatives; D014466:Ultraviolet Rays; D001616:beta-Galactosidase / Q000737:chemistry / Q000276:immunology / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D011506:Proteins; C016952:N-acetyltryptophanamide; D014364:Tryptophan; D001616:beta-Galactosidase