Isoaspartate

The isoaspartate group is a functional group in biochemistry. Its formation is a chemical reaction in which the side chain of an asparagine or aspartic acid residue attacks the following peptide group (in black at top right of Figure 1), 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 iso(Asp), which is a β-amino acid (in green at bottom right). The reaction also results in the deamidation of the asparagine residue.