Microbial cytoplasmic membrane lipids and surface biomolecules

Microbial cytoplasmic membrane lipids and surface biomolecules encompass a wide array of essential structural components that maintain the viability and integrity of bacteria and fungi. In bacteria, the cytoplasmic membrane is primarily composed of phospholipids such as phosphatidylglycerol and cardiolipin, while surface biomolecules include peptidoglycan, teichoic acids in Gram-positive species, and lipopolysaccharides in Gram-negative species (Sohlenkamp & Geiger, 2016, PubMed). Fungal membranes are characterized by the presence of ergosterol, a sterol absent in mammalian cells that regulates membrane fluidity and serves as a critical scaffold for membrane proteins (Mesa-Arango et al., 2012, PubMed). These molecules are critical for functions such as ion homeostasis, nutrient transport, and protection against host immune defenses. Because of their fundamental roles and structural differences from host cells, they are primary targets for several classes of potent antimicrobials. For example, daptomycin targets bacterial membrane lipids to cause rapid depolarization, while polymyxins interact with lipopolysaccharides to disrupt the outer and inner membranes of Gram-negative bacteria (Heidary et al., 2022, PubMed; Trimble et al., 2016, PubMed). Polyene antifungals like amphotericin B bind to ergosterol, creating lethal pores that lead to the leakage of intracellular ions and subsequent cell death (Mesa-Arango et al., 2012, PubMed).

Other names

Microbial cell envelope componentsBacterial cytoplasmic membraneFungal membrane lipidsMicrobial surface moleculesBacterial membrane phospholipids

Drugs targeting these components typically act through membrane depolarization, pore formation, sequestration of essential lipid intermediates like lipid II, or direct disruption of the physical integrity of the phospholipid or sterol-containing bilayer, leading to rapid loss of cytoplasmic contents and cell death.