In lipidomics

Lipidomics

Lipidomics may be defined as the large-scale study of pathways and networks of cellular lipids in biological systems The word "lipidome" is used to describe the complete lipid profile within a cell, tissue or organism and is a subset of the "metabolome" which also includes the three other major...

, the process of shotgun lipidomics (named by analogy with shotgun sequencing

Shotgun sequencing

In genetics, shotgun sequencing, also known as shotgun cloning, is a method used for sequencing long DNA strands. It is named by analogy with the rapidly-expanding, quasi-random firing pattern of a shotgun....

) uses analytical chemistry to investigate the biological function, significance, and sequelae of alterations in lipids and protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 constituents mediating lipid metabolism, trafficking, or biological function in cells. Lipidomics has been greatly facilitated by recent advances in, and novel applications of, electrospray ionization

Electrospray ionization

Electrospray ionization is a technique used in mass spectrometry to produce ions. It is especially useful in producing ions from macromolecules because it overcomes the propensity of these molecules to fragment when ionized...

 mass spectrometry

Mass spectrometry

Mass spectrometry is an analytical technique that measures the mass-to-charge ratio of charged particles.It is used for determining masses of particles, for determining the elemental composition of a sample or molecule, and for elucidating the chemical structures of molecules, such as peptides and...

(ESI/MS).

Lipidomics is a research field that studies the pathways and networks of cellular lipids in biological systems (i.e., lipidomes) on a large scale. It involves the identification and quantification of the thousands of cellular lipid molecular species and their interactions with other lipids, proteins, and other moieties in vivo. Investigators in lipidomics examine the structures, functions, interactions, and dynamics of cellular lipids and the dynamic changes that occur during pathophysiologic perturbations.Lipidomic studies play an essential role in defining the biochemical mechanisms of lipid-related disease processes through identifying alterations in cellular lipid metabolism, trafficking and homeostasis.The two major platforms currently used for lipidomic analyses are HPLC-MS and shotgun lipidomics.

History

Shotgun lipidomics was developed by Richard W. Gross, MD, PhD, and Xianlin Han, PhD., by employing ESI intrasource separation techniques. Individual molecular species of most major and many minor lipid classes can be fingerprinted and quantitated directly from biological lipid extracts without the need for chromatographic purification.

Advantages

Shotgun lipidomics is fast, highly sensitive, and it can identify hundreds of lipids missed by other methods — all with a much smaller tissue sample so that specific cells or minute biopsy samples can be examined.