L-aspartimide (3S)-3-amino-2,5-pyrrolidinedione -18.010564804077148438 -18.020000457763671875 113.03510284423828125 113.09999847412109375 2-amino-butanimide A protein modification that effectively cyclizes an L-asparagine residue to form a carboxyl-terminal L-aspartimide. ASI C 0 H -2 N 0 O -1 C 4 H 5 N 2 O 2 C-term Dehydrated Dehydration From DeltaMass: Average Mass: -17 Average Mass Change:-17 References:Clarke, S., Lability of Aspargine and Aspartic Acid Residues in Protein and Peptides, in: Stability of Protein Pharmaceuticals : Chemical and Physical Paths of Protein Degradation, Part A (T.J. Ahern and M.C. Manning, eds.), 1992,Plenum Press, New York, pp.1-29Xie, M.; Vander Velde, D.; Morton, M.; Borchardt, R.T.; Schowen,R.L.: pH-Induced Change in the Rate-Determining Step for the Hydrolysis of the Asp/Asn-Derived Cyclic-Imide Intermediate in Protein Degradation. (1996) J. Am. Chem. Soc. 118: 8955-8956. L-2-aminosuccinimide L-3-aminosuccinimide L-asparaginimide L-aspartimide MOD:00307 N PSI-MOD Succinimide formation from asparagine Unimod:23 alpha-aminosuccinimide natural cyclized residue dehydrated residue modified L-asparagine residue