ArachidonoylReste

ArachidonoylReste, commonly referred to as an arachidonoyl residue, denotes the acyl fragment derived from arachidonic acid that is attached to a glycerol, sphingolipid, or other lipid backbone. It represents the fatty acyl chain portion of a complex lipid in which the carboxyl group of arachidonic acid forms an ester linkage to the lipid molecule.

In biological membranes, arachidonoyl residues are prevalent in phospholipids, particularly at the sn-2 position of phosphatidylcholine and phosphatidylethanolamine, where they influence membrane fluidity and curvature due to their polyunsaturation. Arachidonic acid itself is a 20-carbon fatty acid with four cis double bonds and serves as an important precursor for eicosanoid biosynthesis.

Functionally, arachidonoyl-containing lipids act as reservoirs for signaling molecules. Upon release by phospholipase A2, free arachidonic acid can be converted by cyclooxygenases, lipoxygenases, and other enzymes into prostaglandins, leukotrienes, and thromboxanes, mediators involved in inflammation, immunity, and hemodynamics. The specific incorporation of an arachidonoyl residue into lipids can thus modulate both local signaling pathways and overall cellular responses.

Analytically, identifying arachidonoyl residues within lipids is important in lipidomics and related studies, aiding in understanding membrane composition, signaling dynamics, and nutritional aspects of fatty acid intake.

See also: arachidonic acid, glycerophospholipids, lipid signaling, eicosanoids.