Lipid bilayer of cell membrane or viral envelope

The **lipid bilayer** (also referred to as the **phospholipid bilayer**) is the fundamental structural component of the membranes surrounding all cells and many viruses[5][1][3][7]. In cells, it forms the plasma membrane, providing a selectively permeable barrier that separates the interior of the cell from the external environment, controls the movement of substances, and supports a variety of embedded proteins for transport, signaling, and cell-to-cell communication[1][5][3][7]. The lipid bilayer consists of two opposing layers of amphiphilic lipid molecules (primarily phospholipids), with hydrophilic head groups facing the aqueous environment and hydrophobic tails facing each other, forming the membrane's core[1][5]. Membrane fluidity and properties are modulated by components such as cholesterol and, in specialized cases, glycolipids[3][7]. For **viruses** with envelopes (e.g., influenza, HIV, coronaviruses), the viral envelope is also made of a lipid bilayer, derived from the host cell membrane as the virus buds off from the host[2][6][8]. Viral envelopes contain viral glycoproteins necessary for host cell attachment and entry, mediating fusion between the viral and host membranes[2][6][8]. The lipid bilayer itself is not a direct drug target. Therapeutic interventions typically focus on proteins or glycoproteins embedded within or associated with the bilayer, such as viral fusion proteins or cellular receptors[2][6][8]. Experimental agents or detergents can disrupt bilayer structure, but this is generally cytotoxic and not a viable therapeutic strategy[5][6]. Due to its ubiquitous structural role and lack of unique molecular features, the lipid bilayer is not classified as a canonical "drug target" such as a receptor, enzyme, or ion channel, but as a **biological membrane** and permeability barrier[5][7]. Drugs interact with or disrupt the bilayer indirectly, primarily as a side effect or in experimental contexts rather than as a focused therapeutic mechanism.

Other names

Phospholipid bilayerCell membrane lipid bilayerViral envelope lipid bilayerPlasma membrane lipid bilayer

Disruption of membrane integrity (cell lysis or viral inactivation, e.g., detergents) Inhibition of membrane fusion (blocking viral entry) Modification of membrane fluidity or lipid composition (affects embedded protein function) None specific for drugs, as lipid bilayer is rarely the primary therapeutic target