Lipids are a group of structurally and functionally diverse organic compounds that are insoluble in water and comprise thousands of different types of molecules. According to LIPIDMAPS classification, lipids are further divided into eight major categories, including Fatty Acyls, Glycerolipids, Glycerophospholipids, Sterol Lipids, Prenol lipids, Sphingolipids, Saccharolipids, Polyketides.
Lipids are widely distributed in cellular organelles and are critical components of all membranes. Lipids could function as second messengers to transduce signals within cells, and serve as important energy sources when nutrients are limited and play an important role in life. Recently studies have shown dysregulation of lipid metabolism contributes to the progression of various metabolic diseases, including cardiovascular diseases, obesity, hepatic steatosis, and diabetes.
Lipidomics aims to study lipids in organisms, different tissues, and cells through various methods, identify their chemical structures, study the molecules that interact with them, and then study the functions of lipids, and finally reveal the relationship between lipids and biological functions. Various strategies have been developed for comprehensive analysis of lipids, including shot-gun and chromatography-coupled mass spectrometry (MS)-based lipidomics.
Fig1. The protocol workflow of lipidomics (Creative Proteomics)
Shot-gun lipidomics directly introduces lipids and detects the lipids by MS, with separation of lipids achieved solely on the basis of mass-to-charge ratio. Creative Proteomics uses a new shotgun lipidomics platform was established by combining an Orbitrap Fusion mass spectrometer with a TriVersa Nanomate nanoelectrospray ion source.
Although shot-gun lipidomics can answer many of the needs associated with sample lipid profiling, some workflows do require chromatographic separation before MS analysis. In these cases, Creative Proteomics would choose a column that is suitable for the separation of your lipids of interest and use ultrahigh-performance liquid/gas chromatography equipped with different mass spectrometry systems to analyze the untargeted lipidomics.