Deamidation (revision 2)
Old revision·17:41, 28 Oct 2024·LiraLotte
This is an old revision of this page, as it stood at 17:41, 28 Oct 2024, saved by LiraLotte with the summary add the note on co-elution and what it hides. It may differ substantially from the current revision, and any error it contains may since have been corrected.
| Deamidation | |
|---|---|
| Residues affected | Asparagine, and more slowly glutamine |
| Mass change | +0.984 Da |
| Charge change | Introduces a negative charge |
| Fastest sequence context | Asn-Gly |
| Topic infobox · conventions | |
Deamidation is the conversion of an asparagine or glutamine side-chain amide to a carboxylic acid, with loss of ammonia. It is among the most common chemical degradation routes in peptides and proteins, and it proceeds spontaneously in aqueous solution without any external agent.[1]
The mass change is +0.984 Da, which is small enough that unit-resolution mass spectrometry cannot distinguish a deamidated peptide from its parent. The charge change is more consequential: an uncharged amide becomes a negatively charged carboxylate, which alters chromatographic behaviour and, in a receptor-binding peptide, may alter activity.[2]
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