Lysobisphosphatidic acid (LBPA) (also known as bis(monoacylglycero)phosphate (BMP)) is a phospholipid that is found in the membranes of late endosomes and lysosomes of eukaryotic cells.
Phosphatidylglycerol is a precursor and structural isomer of LBPA.[1] LBPA's stereochemistry is atypical among glycerophospholipids and influences its function within the LE/LY (late endosome/lysosome) system.[1][2]
LBPA makes up 15–20% of all LE/LY phospholipids and is not found in other subcellular membranes.[3] LBPA is primarily found within the inner LE/LY membranes where they play a role in their structure and trafficking processes.[1][2] In particular, an interaction between NPC2 and LBPA is necessary for intracellular cholesterol trafficking.[1]