Lipidlipiders

Lipidlipiders are a proposed class of lipid-derived biomolecules that combine hydrophobic lipid tails with a polar headgroup derived from a small bioactive moiety. They are hypothesized to function at the interface of membranes and signaling, potentially acting as mediators in intracellular communication or intercellular signaling.

Structural features of lipidlipiders typically include two hydrocarbon tails (diacyl or alkyl chains) linked to a polar headgroup that can bear phosphate, sugar, or amino-acid-like substituents. This dual amphipathic nature enables membrane association and the potential to participate in lipid-protein interactions.

Biosynthesis and metabolism of lipidlipiders are not fully established. Proposed routes involve condensation or transferase-catalyzed linking of two lipid units with a headgroup donor, followed by remodeling by acyltransferases and hydrolases. Enzymes with activities analogous to known lipid transferases may participate, but detailed pathways remain under investigation.

Biological roles attributed to lipidlipiders are speculative and based on their structural properties. They are posited to influence membrane curvature, receptor clustering, and downstream signaling cascades. Lipidlipiders may act as niche mediators in specific tissues or under stress, with their precise functions continuing to be explored.

Detection and research status: Lipidlipiders have been identified in exploratory lipidomics studies using high-resolution mass spectrometry and tandem MS to infer their compositions. Their existence as a distinct and coherent class remains a topic of ongoing research and debate within the lipidomics community.

See also: lipid mediators, lysophospholipids, sphingolipids, lipidomics.