Microbial cell envelope and cytoplasmic membrane

The microbial cell envelope and cytoplasmic membrane constitute the primary structural and protective barriers of bacteria and fungi. The cell envelope typically includes the cell wall—composed of peptidoglycan in bacteria—and, in Gram-negative species, an outer membrane, while the cytoplasmic membrane is a phospholipid bilayer that regulates the transport of solutes and maintains the electrochemical gradient necessary for ATP production [1][2]. These structures are essential for maintaining cell shape, resisting osmotic pressure, and facilitating communication with the environment [3]. Because these components contain elements unique to microbes, such as peptidoglycan or ergosterol, they serve as highly effective targets for antimicrobial therapy [4]. Drugs like beta-lactams and glycopeptides inhibit the synthesis of the cell wall, leading to osmotic lysis, while lipopeptides and polymyxins directly disrupt the integrity of the cytoplasmic membrane [5]. Targeting these structures is a cornerstone of treating infectious diseases, though the emergence of resistance mechanisms, such as modified target sites or efflux pumps, remains a significant clinical challenge [6]. Sources: [1] Silhavy, T. J., et al. (2010). "The Bacterial Cell Envelope." Cold Spring Harbor Perspectives in Biology. [2] Strahl, H., & Hamoen, L. W. (2010). "Membrane potential is important for bacterial cell division." PNAS. [3] Cabeen, M. T., & Jacobs-Wagner, C. (2005). "Bacterial cell shape." Nature Reviews Microbiology. [4] Kohanski, M. A., et al. (2010). "How antibiotics kill bacteria: from targets to networks." Nature Reviews Microbiology. [5] Silver, L. L. (2011). "Challenges of Antibacterial Discovery." Clinical Microbiology Reviews. [6] Blair, J. M., et al. (2015). "Molecular mechanisms of antibiotic resistance." Nature Reviews Microbiology.

Other names

Bacterial cell envelopeBacterial cell wallCytoplasmic membranePlasma membranePeptidoglycan layerOuter membraneMicrobial barrier

Inhibition of peptidoglycan cross-linking by binding to penicillin-binding proteins (PBPs); binding to D-Ala-D-Ala precursors to inhibit cell wall synthesis; disruption of the cytoplasmic membrane through pore formation or depolarization; binding to lipopolysaccharides (LPS) in the outer membrane of Gram-negative bacteria; inhibition of ergosterol synthesis or direct binding to ergosterol in fungal membranes.