Biomaterial Database

Deamidation via cyclic imide in asparaginyl peptides. 1989

S Capasso, and L Mazzarella, and F Sica, and A Zagari

Dipartimento di Chimica, Università di Napoli, Italy.

The deamidation reaction of asparaginyl peptides was studied as a function of the pH and sequence. The deamidation of Boc-Asn-Gly-Gly-NH2 and the hydrolysis of the corresponding aminosuccinyl (Asu) peptide, Boc-Asu-Gly-Gly-NH2, were carried out in the pH ranges 5-10, whereas the deamidation of Boc-Asn-Ala-Gly-NH2, Boc-Asn-Gly-Ala-NH2 and Boc-Asn-Ser-Gly-NH2 was studied at pH 8.9 only. In each case, the conversion of the amide side-chain moiety of the Asn to carboxyl group occurs via a succinimide intermediate (Asu), and its breakdown leads to a normal and an isoaspartyl peptide. The kinetic constants of the Asu formation and the hydrolytic step increase markedly at basic pH. The influence of the side chain of the residue next to Asn is also discussed.

UI	MeSH Term	Description	Entries
D007094	Imides	Organic compounds containing two acyl groups bound to NITROGEN.	Imide
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009842	Oligopeptides	Peptides composed of between two and twelve amino acids.	Oligopeptide
D010455	Peptides	Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are considered to be larger versions of peptides that can form into complex structures such as ENZYMES and RECEPTORS.	Peptide,Polypeptide,Polypeptides
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D006868	Hydrolysis	The process of cleaving a chemical compound by the addition of a molecule of water.
D000577	Amides	Organic compounds containing the -CO-NH2 radical. Amides are derived from acids by replacement of -OH by -NH2 or from ammonia by the replacement of H by an acyl group. (From Grant & Hackh's Chemical Dictionary, 5th ed)	Amide
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D001216	Asparagine	A non-essential amino acid that is involved in the metabolic control of cell functions in nerve and brain tissue. It is biosynthesized from ASPARTIC ACID and AMMONIA by asparagine synthetase. (From Concise Encyclopedia Biochemistry and Molecular Biology, 3rd ed)	L-Asparagine