Peptide Bond Hydrolysis — A Stability Reference Review

Peptide bond hydrolysis is the primary chemical degradation pathway affecting lyophilized and reconstituted research peptides. This brief reviews the conditions that accelerate or retard cleavage and the practical implications for storage.

Hydrolysis Mechanisms

The amide bond is kinetically stable at neutral pH and room temperature but susceptible to acid- and base-catalyzed hydrolysis. The hydroxide ion adds to the carbonyl carbon, forming a tetrahedral intermediate that collapses with loss of the amine. Activation energy for spontaneous hydrolysis is approximately 90 kJ/mol at pH 7.

Cleavage-Prone Sequences

Asp-Pro and Asp-Gly bonds hydrolyze ~100× faster than average peptide bonds at low pH due to neighboring-group participation by the aspartate carboxylate. Met residues are also prone to oxidation, often preceding bond cleavage.

Storage Implications

• Lyophilized at −20 °C, desiccated: hydrolysis rate <0.1% / year for most peptides
• Reconstituted in bacteriostatic water at 2–8 °C: typical loss 1–3% over 28 days
• Room temperature in solution: measurable cleavage within days

References

See References for full citations of the source literature on peptide stability under varied pH, temperature, and ionic conditions.

RUO. Reference material for laboratory storage planning.