Bacterial cellular membrane

The bacterial cellular membrane is a fundamental phospholipid bilayer that encloses the cytoplasm and serves as a primary site for energy transduction, nutrient transport, and cell signaling (Sohlenkamp & Geiger, 2016, FEMS Microbiology Reviews). It is distinct from eukaryotic membranes due to the absence of sterols like cholesterol and a high proportion of negatively charged lipids such as phosphatidylglycerol, which facilitates the selective binding of cationic antimicrobial peptides and lipopeptides (Epand et al., 2016, Biochimica et Biophysica Acta). In Gram-negative bacteria, the inner membrane is complemented by an outer membrane, whereas Gram-positive bacteria possess a single cytoplasmic membrane (Silhavy et al., 2010, Cold Spring Harbor Perspectives in Biology). Therapeutic agents like daptomycin and polymyxins target this structure to cause rapid depolarization or physical disruption, leading to the leakage of essential ions and cell death (Humphries et al., 2017, Clinical Infectious Diseases). Because the membrane's integrity is essential for bacterial viability, it represents a robust target for treating multi-drug resistant infections, although potential cross-reactivity with host membranes can lead to side effects like nephrotoxicity or myopathy (Falagas & Kasiakou, 2006, Critical Care).

Other names

Bacterial cytoplasmic membraneBacterial plasma membraneBacterial inner membraneProtoplast membrane

Drugs targeting the bacterial cellular membrane primarily act through physical disruption of the lipid bilayer or the dissipation of the proton motive force. For instance, daptomycin inserts into the membrane in a calcium-dependent manner, leading to potassium efflux and rapid depolarization (Silverman et al., 2003, Antimicrobial Agents and Chemotherapy). Polymyxins act as detergents, binding to the lipid A component of lipopolysaccharides and phospholipids to disrupt the integrity of both the inner and outer membranes (Velkov et al., 2013, Journal of Medicinal Chemistry).