Asn and Gln can be considered as derivatives of Asp and Glu. The side-chain carboxy groups of these amino acids have been converted into carboxamides. Isoasparagine and isoglutamine result when amidating the α-carboxy moiety. The β-carboxyl of Isoasn and the γ-carboxy group of Isogln can participate in peptide bonds.
L-Isoasparagine: H-Asp-NH2
L-Isoglutamine: H-Glu-NH2
Isoasparagine derivatives are assembled in a subfamily filed under Aspartic Acid, isoglutamine derivatives can be found in the Glutamic Acid family.