Antibiotic amphotericin B–DPPC lipid complex: X-ray diffraction and FTIR studies

• Amphotericin B–DPPC complex formation and dissociation.
• Characteristic reflection from the amphotericin B–DPPC complex in X-ray diffraction.
• Amphotericin B–DPPC complex organization in lipid multibilayers in function of temperature.

In this work, we studied the formation of a complex between the polyene antibiotic amphotericin B (AmB) and dipalmitoylphosphatidylcholine (DPPC) lipid multibilayers by means of X-ray diffraction and FTIR spectroscopy. The complex formation can be detected in multibilayers by characteristic reflection around 2.2 Å−1. The FTIR spectra indicate that in this case AmB lowers the main phase transition of DPPC. Additionally, with an increase in temperature, a shift of AmB towards the hydrophilic part of the DPPC bilayer is observed. For the first time, such complex formation has been observed by X-ray diffraction and discussed.