Peptide Stability in Solids and Solutions

Abstract

A discussion of the factors influencing peptide stability illustrates the challenges of formulation and shelf-life prediction which face biotechnologists. The activation energies of peptide degradation vary with pH and moisture content. Peptide degradation rates are influenced by both buffer type and concentration. Lyophilization results in an increase in buffer concentration which also enhances peptide degradation in low-moisture solids. Small peptides have degradation rates that depend upon water activity rather than upon mobility limitations associated with the state of the system. The pH-rate profiles for peptide degradation in solution and solids are quite different. Dehydration and partial rehydration change the pH of reduced-moisture solids, which change both the rates and mechanisms of degradation. The properties of the peptide and the system as well as potential interactions between the two need to be identified to maximize peptide stability. In addition, solution data cannot be used to predict the shelf life of reduced-moisture solids.

Development of high throughput 96-blade solid phase microextraction-liquid chromatrography-mass spectrometry protocol for metabolomics

“…This conversion can occur in peptides containing asparagine in the N terminal. Chiral integrity of amino acids and peptides can happen as well [39]. In the present study, 2,5-Dioxopiperazine and pyroglutamic acid are two differentiate metabolites increased in 10h samples versus 0h ones.…”

Evaluation of the physical and in vitro protective activity of three synthetic peptides derived from the pro- and mature GDNF sequence

“…Because of the stringent requirements of biotherapeutics for in vitro stability and solubility, the DNSPs were evaluated for these properties (Bell, 1997; Powell, 1994). RP-HPLC and LC-MS data showed that each of the DNSPs were stable at −80 °C and 37 °C for one month without any appreciable loss or intrinsic modification of the peptides.…”

Molecular Dynamics of Solid-State Lysozyme as Affected by Glycerol and Water: A Neutron Scattering Study

“…Proteins are frequently produced via lyophilization, and polyols are often utilized as cryoprotectants. Factors that affect the physical and chemical stability of lyophilized peptides and proteins include temperature, pH, residual moisture content, and the presence of excipients (Bell, 1997). Differential scanning calorimetry (DSC) has shown that the thermal stability of dehydrated lysozyme and somatotropin decreases with increasing moisture, irrespective of the excipients (Bell et al, 1995b).…”