X-RAY STUDIES ON PHOSPHOLIPID-BILAYERS .13. INTERACTIONS WITH GENTAMICIN

This study deals with the structural perturbations that the aminoglyco side antibiotic gentamicin (GENT) can produce to phospholipid bilayers . Two multibilayer systems, one built-up of dimyristoylphosphatidylcho line (DMPC) and the other of dimyristoylphosphatidylethanolamine (DMPE ) were allowed to interact with GENT. The experiments were performed i n both a hydrophobic and a hydrophilic medium below the phospholipid m ain transition temperatures. X-ray diffraction techniques were used to determine the extent of the perturbation induced by GENT. The maximum effect was attained when GENT interacted with DMPC in the hydrophobic medium. On the other hand, GENT in aqueous solutions was unable to pe rturb in any significant extent the structure of the phospholipids und er study.