Sphingomyelin (from bovine brain) contains primarily of stearic and nervonic acids. Structurally Sphingomyelin has a ceramide core and a sphingosine bonded to a fatty acid via an amide linkage. The compound is synthesized in the cis/medial-Golgi and is a precursor to ceramide second messengers via the action of sphingomyelinase. This is found to have a function in signal transduction. The plasma membrane of cells is highly enriched in sphingomyelin (SPH) and is considered largely to be found in the exoplasmic leaflet of the cell membrane. Transport of sphingomyelin to the cell surface has been demonstrated to occur independent of protein secretion in rat hepatocytes. It has been observed that sphyngomyelin is a key molecule for ganglioside-bound amyloid β-protein generation on the surface of PC12 cells.
