Shotgun proteomics

Proteomics

Proteomics is the large-scale study of proteins, particularly their structures and functions. Proteins are vital parts of living organisms, as they are the main components of the physiological metabolic pathways of cells. The term "proteomics" was first coined in 1997 to make an analogy with...

is a method of identifying 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...

s in complex mixtures using a combination of high performance liquid chromatography

High performance liquid chromatography

High-performance liquid chromatography , HPLC, is a chromatographic technique that can separate a mixture of compounds and is used in biochemistry and analytical chemistry to identify, quantify and purify the individual components of the mixture.HPLC typically utilizes different types of stationary...

 combined with 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...

. The name is derived from 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....

 of DNA

DNA

Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...

 which is itself named by analogy with the rapidly-expanding, quasi-random firing pattern of a shotgun

Shotgun

A shotgun is a firearm that is usually designed to be fired from the shoulder, which uses the energy of a fixed shell to fire a number of small spherical pellets called shot, or a solid projectile called a slug...

. In shotgun proteomics, the proteins in the mixture are digested

Protease

A protease is any enzyme that conducts proteolysis, that is, begins protein catabolism by hydrolysis of the peptide bonds that link amino acids together in the polypeptide chain forming the protein....

 and the resulting peptide

Peptide

Peptides are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond...

s are separated by liquid chromatography. Tandem mass spectrometry

Tandem mass spectrometry

Tandem mass spectrometry, also known as MS/MS or MS2, involves multiple steps of mass spectrometry selection, with some form of fragmentation occurring in between the stages.-Tandem MS instruments:...

 is then used to identify the peptides.

See also

• Shotgun lipidomics
  Shotgun lipidomics
  In lipidomics, the process of shotgun lipidomics uses analytical chemistry to investigate the biological function, significance, and sequelae of alterations in lipids and protein constituents mediating lipid metabolism, trafficking, or biological function in cells...
  
  
• Protein mass spectrometry
  Protein mass spectrometry
  Protein mass spectrometry refers to the application of mass spectrometry to the study of proteins. Mass spectrometry is an important emerging method for the characterization of proteins. The two primary methods for ionization of whole proteins are electrospray ionization and matrix-assisted laser...
  
  
• Bottom-up proteomics
  Bottom-up proteomics
  Bottom-up proteomics is a common method to identify proteins and characterize their amino acid sequences and post-translational modifications by proteolytic digestion of proteins prior to analysis by mass spectrometry. The proteins may first be purified by a method such as gel electrophoresis...
  
  
• Top-down proteomics
  Top-down proteomics
  Top-down proteomics is a method of protein identification that uses an ion trapping mass spectrometer to store an isolated protein ion for mass measurement and tandem mass spectrometry analysis. The name is derived from the similar approach to DNA seqencing...
  
  
• Mass spectrometry software
  Mass spectrometry software
  Mass spectrometry software is software used for data acquisition, analysis, or representation in mass spectrometry.- MS/MS peptide identification :...