Bacterial cytoplasmic membrane and cell envelope

The bacterial cytoplasmic membrane and associated cell envelope components constitute the fundamental structural barrier of prokaryotic cells, essential for maintaining osmotic pressure and cellular homeostasis (Silhavy et al., 2010, Cold Spring Harb Perspect Biol). The cytoplasmic membrane is a phospholipid bilayer that serves as a scaffold for proteins involved in energy production, such as the electron transport chain, and the transport of nutrients and waste (Strahl & Hamoen, 2010, PNAS). In most bacteria, this membrane is protected by a cell envelope consisting of a peptidoglycan cell wall, which provides mechanical strength and prevents osmotic lysis (Vollmer et al., 2008, FEMS Microbiol Rev). In Gram-negative species, an additional outer membrane containing lipopolysaccharides provides an extra layer of protection against environmental stressors and antibiotics (Nikaido, 2003, Microbiol Mol Biol Rev). These structures are critical therapeutic targets; for instance, polymyxins and daptomycin directly disrupt membrane integrity, while beta-lactams and glycopeptides inhibit the synthesis of the cell wall (Silver, 2011, Clin Microbiol Rev). Because the composition of the bacterial cell envelope differs significantly from human cell membranes, it allows for the development of drugs with high selective toxicity, although the emergence of resistance remains a significant clinical challenge (Blair et al., 2015, Nat Rev Microbiol).

Other names

Bacterial inner membranePlasma membraneCell wallPeptidoglycan layerBacterial cell envelopeBacterial cytoplasmic membrane

Disruption of membrane integrity, pore formation, depolarization of the cytoplasmic membrane, and inhibition of cell wall (peptidoglycan) biosynthesis (Silver, 2011, Clin Microbiol Rev; Strahl & Hamoen, 2010, PNAS).