Deamidation

Deamidation is a chemical reaction in which an amide functional group is removed from an organic compound. In biochemistry, the reaction is important in the degradation of proteins because it damages the amide-containing side chains of the amino acids asparagine and glutamine.

In the biochemical deamidation reaction, the side chain of an asparagine attacks the following peptide group (in black at top right of Figure), forming a symmetric succinimide intermediate (in red). The symmetry of the intermediate results in two products of its hydrolysis, either aspartate (in black at left) or in isoaspartate, which is a beta amino acid (in green at bottom right). This process is considered a deamidation because the amide in the asparagine side chain is replaced by a carboxylate group. However, a similar reaction can occur in aspartate side chains, yielding a partial conversion to isoaspartate.

Read more about Deamidation:  Kinetics of Deamidation

Other articles related to "deamidation":

Triticeae Glutens - Triticeae Glutens and Industry - Gluten Deamidation
... The deamidation potential for wheats is discussed above ... gluten is often modified for commercial use by deamidation by treatment with acid at high temperatures, or enzymatic treatment with deamidase or transglutaminases ... Deamidation of 20% of glutamine side chains to glutamate suffices to generate a soluble product ...
Tissue Transglutaminase - Mechanism
... deamidation) ... The deamidation of glutamine residues catalyzed by tTG is thought to be linked to the pathological immune response to gluten in celiac disease ... A schematic for the crosslinking and the deamidation reactions is provided in Figure 1 ...
Coeliac Disease - Pathophysiology - Tissue Transglutaminase
... These peptides are modified by tTG in two ways, deamidation or transamidation ... Deamidation is the reaction by which a glutamate residue is formed by cleavage of the epsilon-amino group of a glutamine side chain ... Transamidation, which occurs three times more often than deamidation, is the cross-linking of a glutamine residue from the gliadin peptide to a lysine residue of tTg in a reaction which is ...
Kinetics of Deamidation
... Deamidation reactions have been conjectured to be one of the factors that limit the useful lifetime of proteins ... Deamidation proceeds much more quickly if the susceptible amino acid is followed by a small, flexible residue such as glycine whose low steric hindrance leaves the peptide group open for attack ... Deamidation reactions also proceed much more quickly at elevated pH (>10) and temperature ...