Dipalmitoylglycerol (DPG) is a specific diacylglycerol (DAG) species featuring two palmitic acid (C16:0) chains esterified at the sn-1 and sn-2 positions of a glycerol backbone. This synthetic lipid analog serves as a potent tool for studying second messenger signaling and membrane dynamics, complementing studies of the broader DAG family.
Chemical Structure
DPG has the molecular formula C35H68O5 and a molecular weight of 568.9 g/mol. Its chiral sn-glycerol configuration with symmetric saturated palmitoyl chains yields a cylindrical shape (packing parameter ~1), favoring lamellar over inverted phases.
Physical Properties
Crystallizing in a monoclinic P21 space group at 123 K (a=5.480 Å, b=7.301 Å), DPG appears as a white waxy solid with high hydrophobicity (XLogP3-AA ~14), topological polar surface area of 72.8 Ų, and collision cross-sections of 252.1 Ų [M+Na]+ and 254.9 Ų [M+K]+. It is soluble in chloroform, ethyl acetate, and DMSO but insoluble in water, and stores stably at 2–8°C.
Biological Functions
As a 1,2-DAG regioisomer, DPG activates protein kinase C (PKC) isoforms by ~15% via C1 domain binding, mimicking phospholipase C-generated signals in phosphoinositide hydrolysis. It promotes negative membrane curvature, lipid domain formation, and vesicle fusion without causing toxicity in cellular assays.