Controlling deamidation rates in a model peptide: Effects of temperature, peptide concentration, and additives

Lewis P. Stratton, R. Michael Kelly, Jared Rowe, Jesse E. Shively, D. David Smith, John F. Carpenter, Mark C. Manning

Research output: Contribution to journalArticlepeer-review

53 Scopus citations


The rate of deamidation of the Asn residue in Val- Tyr-Pro-Asn-Gly-Ala (VYPNGA), a model peptide, was determined at pH 9 (400 mM Tris buffer) as a function of temperature and peptide concentration. Over the temperature range 5-65°C, deamidation followed Arrhenius behavior, with an apparent activation energy of 13.3 kcal/mol. Furthermore, increasing the peptide concentration slows the rate of deamidation. Self-stabilization with respect to deamidation has not been reported previously. The rate of deamidation was also determined in the presence of sucrose and poloxamer 407 (Pluronic F127). In both cases, the rate of deamidation was retarded by up to 40% at 35°C. In aqueous solutions containing poloxamer 407, the degree of stabilization is independent of formation of a reversible thermosetting gel. With sucrose, maximum reduction in the deamidation rate was attained with as little as 5% (w/v). Addition of sucrose results in a greater conformational preference for a type II β-turn structure, which presumably is less prone to intramolecular cyclization and subsequent deamidation.

Original languageEnglish (US)
Article number50003505
Pages (from-to)2141-2148
Number of pages8
JournalJournal of Pharmaceutical Sciences
Issue number12
StatePublished - 2001

All Science Journal Classification (ASJC) codes

  • Pharmaceutical Science


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