Microbial cytoplasmic cell membrane lipid bilayer

The microbial cytoplasmic cell membrane lipid bilayer is a fundamental structural component of bacteria and fungi, acting as a selective barrier that regulates the internal environment. It consists of a phospholipid bilayer embedded with proteins responsible for essential processes such as nutrient transport, signal transduction, and ATP synthesis via the electron transport chain (Wikipedia: Bacterial cell structure). In many pathogens, this membrane is the site of cell wall precursor synthesis, making its integrity crucial for overall structural stability and survival. As a therapeutic target, it is exploited by several classes of antibiotics and antifungals, including lipopeptides, polymyxins, and polyenes. These drugs typically act by inserting into the membrane, leading to pore formation or depolarization, which causes the leakage of vital intracellular components like potassium ions and results in rapid cell death (PMID: 26275872). The selectivity of these agents often relies on the unique lipid composition of microbial membranes, such as the presence of ergosterol in fungi or specific anionic phospholipids in bacteria, which are distinct from the cholesterol-rich membranes of mammalian cells.

Other names

Bacterial cytoplasmic membraneProkaryotic inner membraneMicrobial plasma membraneFungal plasma membraneBacterial cell membrane

Drugs targeting the microbial cytoplasmic membrane typically act through physical disruption or functional impairment. Lipopeptides like daptomycin aggregate within the membrane in a calcium-dependent manner, creating complexes that cause rapid potassium efflux and depolarization (PMID: 24388738). Polymyxins interact with phospholipids to disrupt the integrity of both the outer and inner membranes of Gram-negative bacteria, leading to cytoplasmic leakage (StatPearls: Polymyxins). Polyene antifungals like amphotericin B bind to ergosterol, forming transmembrane pores that allow the leakage of monovalent ions and metabolites, resulting in fungal cell death (NCBI: Bookshelf NBK545284).