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Peptide Mapping

  1. Gang Chen

Published Online: 15 APR 2014

DOI: 10.1002/9780470015902.a0002675.pub2

eLS

eLS

How to Cite

Chen, G. 2014. Peptide Mapping. eLS. .

Author Information

  1. Fudan University, Shanghai, China

Publication History

  1. Published Online: 15 APR 2014

Abstract

Proteomics is the large-scale study of proteins, particularly their structures and functions. One of its most important tasks is to develop efficient and rapid approaches to identify various proteins. Peptide mapping is a commonly used strategy in protein identification. It involves the chemical or enzymatic treatment of proteins resulting in the formation of peptide fragments followed by separation and identification of the resultant fragments. Proteins are usually digested into peptides that are subsequently identified by mass spectrometry to obtain peptide mass fingerprints. Peptide mapping is an important technique for investigating protein primary structures and determining surface-exposed sites or epitopes within proteins. It can be adapted to obtain internal protein sequences. Prior to identification, the proteins and peptides usually need to be separated by a variety of separation approaches, such as gel electrophoresis, liquid chromatograph, capillary electrophoresis, etc.

Key Concepts:

  • Sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS-PAGE) is a commonly used approach for the separation of proteins and peptides.

  • Two-dimensional gel electrophoresis (2-DE) can separate a great many of proteins in two separation modes.

  • Proteolysis is a process where proteins are broken down into smaller peptides by proteases.

  • Proteases are enzymes that conduct proteolysis by hydrolysis of some specific peptide bonds.

  • Mass spectroscopy (MS) is an analytical technique to separate the components of a sample by their mass-to-charge ratios.

  • Peptide mass fingerprinting is the most popular analytical application of matrix-assisted laser desorption/ionisation-time of flight MS (MALDI-TOF MS) and electrospray MS.

  • Electrospray became widely used as ionisation source for the MS analysis of proteins and peptides.

  • Mascot is a powerful search engine which uses mass spectrometry data to identify proteins from primary sequence databases.

  • Sequence coverage is the percentage of the database protein sequence covered by matching peptides.

  • Proteolytic microchip bioreactors are microdevices in which proteases are immobilised for efficient peptide mapping.

Keywords:

  • peptide;
  • separation;
  • SDS-PAGE;
  • 2-DE;
  • mass spectrometry;
  • peptide mass fingerprinting