Negatively charged phospholipid

Negatively charged phospholipids are a structural class of phospholipids in which the head group contains a net negative charge at physiological pH. The negative charge is typically due to the presence of a phosphate group (as in phosphatidic acid, phosphatidylglycerol, phosphatidylinositol) or additional charged side chains (as in phosphatidylserine). These molecules are major components of biological membranes, where they contribute to the asymmetry and selective permeability of the lipid bilayer[2][3][7]. The hydrophilic "head" contains the negatively charged phosphate moiety, while the hydrophobic "tails" comprise two fatty acids[4][7]. Negatively charged phospholipids interact with a variety of proteins, especially those involved in signaling, membrane fusion, and vesicle trafficking[5]. Importantly, their uneven distribution helps distinguish cell types and physiological states: for example, pathogens may have a much higher surface density of negatively charged phospholipids than host eukaryotic cells, and in mammalian cells, some (like phosphatidylserine) are sequestered on the inner leaflet except during apoptosis or cell stress[5]. Because of these selective distributions, several antimicrobial proteins and peptides exploit negatively charged phospholipids as a means of targeting pathogens, and externalized phosphatidylserine is a biomarker for apoptosis[5]. Phospholipids as a chemical class are not considered a therapeutic target (receptor, enzyme, transporter, etc.), but specific negatively charged phospholipid species (most notably phosphatidylserine) can play crucial roles in pathology and can be selectively recognized by engineered drugs, antibodies, or proteins[5].

Other names

Anionic phospholipidacidic phospholipid