Tryptophan fluorescence quenching study on AFV3-109. The tryptophan fluorescence quenching titration of AFV3-109 at 336 nm emission wavelength (expressed as 1-I/I0, with I0 the intensity of fluorescence in absence of quencher and I the intensity of fluorescence upon addition of quencher). Titration with glycerol (A) and dsDNA (B). The KDapp values are calculated from the fitting of the data to a single exponential (GraphPad). Inset, fluorescence emission spectra in the presence of increasing concentrations of glycerol or dsDNA.