Edman degradation

Source: Wikipedia, the free encyclopedia.

Edman degradation, developed by

peptide bonds
between other amino acid residues.

Mechanism

Edman degradation with generic amino acid peptide chain

pico-moles of peptide for the sequencing process. The Edman degradation reaction was automated in 1967 by Edman and Beggs to speed up the process[2] and 100 automated devices were in use worldwide by 1973.[3]

Limitations

Because the Edman degradation proceeds from the N-terminus of the protein, it will not work if the N-terminus has been chemically modified (e.g. by acetylation or formation of pyroglutamic acid). Sequencing will stop if a non-α-amino acid is encountered (e.g. isoaspartic acid), since the favored five-membered ring intermediate is unable to be formed. Edman degradation is generally not useful to determine the positions of disulfide bridges. It also requires peptide amounts of 1 picomole or above for discernible results.

Coupled analysis

Following 2D SDS PAGE the proteins can be transferred to a polyvinylidene difluoride (PVDF) blotting membrane for further analysis. Edman degradations can be performed directly from a PVDF membrane. N-terminal residue sequencing resulting in five to ten amino acid may be sufficient to identify a Protein of Interest (POI).

See also

References