X-ray studies on phospholipid bilayers. X. Interactions with chlortetracycline hydrochloride.

This study deals with the structural perturbations that the antibiotic chlortetracycline hydrochloride (CTC) can produce on phospholipid bilayers. Two multibilayer systems, one built-up of dimyristoylphosphatidylethanolamine (DMPE) and the other of dimyristoylphosphatidylcholine (DMPC) were allowed to interact with different concentrations of CTC in the absence and presence of water. The study was carried out by X-ray diffraction methods and all experiments were done below the phospholipid main transition temperatures. The results showed that CTC produced significant perturbations on DMPC even in the absence of water, whereas they were much milder in DMPE.