of its interaction with other biological species. Notably, phosphatidylcholine lipids, with their bulky tetramethylammonium headgroup, play a fundamental role in mediating the interactions of membrane proteins with those in the extracellular space. This study focuses on the interactions between TMA and anionic species, specifically the carboxylate groups present, for example, in anionic amino acid side chains (Asp and Glu) and anionic sugars. Most cell surfaces are decorated with glycosylations rich in carboxylated molecular groups, either attached to plasma proteins through terminal sialic acid groups of their N-glycosylations or present in the extracellular space surrounding plasma membranes, as in hyaluronic acid. Therefore, the interaction of the cationic TMA motifs of phosphatidylcholine lipids with these carboxylate groups in anionic sugars and amino acids is of direct biological relevance.