Bacterial cell outer membrane

The **bacterial cell outer membrane** is a characteristic feature of Gram-negative bacteria, forming the outermost layer of the cell envelope and encapsulating the periplasmic space, which lies between it and the inner cytoplasmic membrane[1][2]. The outer membrane is an asymmetric bilayer composed of phospholipids (inner leaflet) and lipopolysaccharide (LPS; outer leaflet). LPS consists of lipid A (endotoxin), core oligosaccharide, and variable O-antigen. The membrane contains various proteins, including porins (channels for small molecule diffusion), substrate-specific transporters, lipoproteins, and efflux pumps[1][4][7]. Unlike typical biological membranes, many outer membrane proteins adopt anti-parallel beta-barrel structures. Biologically, the outer membrane provides a robust permeability barrier, protecting bacteria from antibiotics, toxins, and harsh environments, anchoring virulence factors, mediating interactions with hosts, and contributing to structural integrity and cell morphogenesis[3][5][7]. Clinical significance arises from its LPS component: lipid A is a potent activator of the immune system and can cause endotoxic shock, while the OM’s impermeability complicates antibiotic therapy and promotes multidrug resistance[1][5]. Although individual proteins and components of the bacterial outer membrane are direct drug targets, the **outer membrane itself is a cellular structure, not a canonical therapeutic target such as a receptor, enzyme, or transporter**. **Explanation:** - The term "Bacterial cell outer membrane" refers to a complex cell structure and not a single molecular target, protein, or canonical drug target class such as a receptor or enzyme[2]. - Its components (lipopolysaccharide, porins, efflux pumps) may be targets, but the entire structure is not conventionally listed as such in drug hunting or medical databases[1][4][5]. - Therefore, **is_target: false** and **is_incorrect: true** (too broad, not a molecular target in the sense typical to drug discovery; should be decomposed into its protein or lipid components for target lists).

Other names

Bacterial outer membraneGram-negative bacterial outer membraneOuter membrane (OM)

Disruption of membrane integrity (polymyxins bind LPS, increase permeability, and cause cell death) - Chelation of divalent cations (EDTA destabilizes OM, sensitizing bacteria to other agents) - Passive diffusion/porin-mediated entry for some antibiotics