Binding of InlB to MET induces receptor dimerization. Single-molecule data were background-corrected and single-fluorophore intensity distributions extracted. (A) Individual fluorescence spots of single InlB-ATTO647N adsorbed to an L-lysine coated glass surface (top). Fluorescence spots selected for intensity analysis are marked with green squares (7x7 pixels) (scale bar 2 μm). The intensity distribution of individual InlB-ATTO647N molecules (n = 404) was well fitted with a single Gaussian function. (B) TIRF image of an uninduced cell. The distribution of fluorescence intensities was fitted by two Gaussian functions (n = 527 spots from 17 cells were analyzed). (C) TIRF image of an induced cell. The intensity distribution shows an increase of the fraction of receptor dimers (n = 421 spots from 10 cells). Numbers on histograms indicate maxima and fractions.
Dietz et al. BMC Biophysics 2013 6:6 doi:10.1186/2046-1682-6-6