Fig. 6.

Natamycin binds to the liquid-ordered phase in a sterol-dependent manner.

Structure of natamycin with conjugated double bonds (blue-shaded region) giving rise to its fluorescence are shown in A. Excitation (dashed blue line) and emission spectra (straight blue line) with overlayed bandpass of excitation and emission filter of the UV-optimized microscope used to image natamycin (B). GUVs consisting of POPS/SSM and either ergosterol or cholesterol are shown in C with natamycin in red and NBD-PC as a marker for the Ld phase in green. Line scans were performed over example vesicles indicating partitioning of natamycin (red) and NBD-PC (green) in GUVs containing either ergosterol (D) or cholesterol (E). From these scans, the percentage binding of natamycin to GUVs was quantified to the Lo phase (lacking NBD-PC, red) or Ld phase (containing NBD-PC, green) with either ergosterol or cholesterol (F). See main text for further explanations.