Phospholipid enrichment of Saccharomyces cerevisiae and its effect on polyene sensitivity

Sensitivity to polyene antibiotics, e.g., nystatin, amphotericin B, and filipin, was determined in phosphatidylcholine (PC) or phosphatidylethanolamine (PE) or phosphatidylserine (PS) enriched Saccharomyces cerevisiae cells, using glutamic acid, phenylalanine, glycine, and lysine transport as an index of polyene antibiotic action. As compared with normal cells, phospholipid-enriched cells acquired resistance towards different polyenes. However, the sensitivity of glutamic acid transport towards nystatin remained unaffected in PC-, PE-, or PS-enriched cells. In contrast to nystatin, the other two polyenes were more effective in checking the influx of amino acids. Results demonstrated that the specific enrichment of PC, PE, or PS could selectively protect S. cerevisiae cells from polyene antibiotic action.