Deamidation, isomerization, and racemization at asparaginyl and aspartyl residues in peptides. Succinimide-linked reactions that contribute to protein degradation.

In 1989, Manning, Patel, and Borchardt wrote a review of protein stability (Manning et al, Pharm Res 6:903-918, 1989), which has been widely referenced ever since At the time, recombinant protein therapy was still in its infancy This review summarizes the advances that have been made since then regarding protein stabilization and formulation In addition to a discussion of the current understanding of chemical and physical instability, sections are included on stabilization in aqueous solution and the dried state, the use of chemical modification and mutagenesis to improve stability, and the interrelationship between chemical and physical instability

Stability of Protein Pharmaceuticals: An Update

Two dimensional gel electrophoresis and computer analysis of proteins synthesized by clonal cell lines.

A convenient and precise mass spectrometric method for measurement
 of the deamidation rates of glutaminyl and asparaginyl residues in
 peptides and proteins has been developed; the rates of deamidation of
 306 asparaginyl sequences in model peptides at pH 7.4, 37.0°C, 0.15 M
 Tris⋅HCl buffer have been determined; a library of 913
 amide-containing peptides for use by other investigators in similar
 studies has been established; and, by means of simultaneous deamidation
 rate measurements of rabbit muscle aldolase and appropriate model
 peptides in the same solutions, the use of this method for quantitative
 measurement of the relative effects of primary, secondary, tertiary,
 and quaternary protein structure on deamidation rates has been
 demonstrated. The measured rates are discussed with respect to the
 hypothesis that glutaminyl and asparaginyl residues serve, through
 deamidation, as molecular timers of biological events.

https://www.pnas.org/content/pnas/98/3/944.full.pdf

Molecular clocks

Succinimide formation from aspartyl and asparaginyl peptides as a model for the spontaneous degradation of proteins.

Publisher Summary This chapter discusses the deamidation of glutaminyl and asparaginyl residues in peptides and proteins. The occurrence of glutaminyl and asparaginyl residues in peptides and proteins is so widespread that these residues have become known as 2 of the 20 most commonly occurring amino acid residues. It has been hypothesized that these residues play static roles in protein structure and also play dynamic roles as molecular timers of biological events. Deamidation of glutaminyl and asparaginyl residues has been responsible for artifacts in peptide and protein chemistry. The rate of deamidation of these residues has been shown to be dependent upon primary sequence, secondary and tertiary structure, temperature, pH, ionic strength, and special intermolecular interactions. Deamidation has been found to occur in a wide variety of different proteins and may be expected to occur in most proteins under physiological conditions. Many of the essential processes in living things may be timed by deamidation of glutaminyl and asparaginyl residues. These molecular timers are under simple genetic control, are adjustable to many different timed intervals, and are easily implementable by means of the important changes that they can effect in the proteins in which they are included.

Deamidation of Glutaminyl and Asparaginyl Residues in Peptides and Proteins

Disulfide-linked, triple-stranded procollagen (pro γ 112) was isolated from chick embryo skull bones. It was reversibly denatured and renatured as judged by sedimentation properties and susceptibility to digestion with pepsin. Refolding was an intramolecular process and aggregation between molecules did not occur.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/jss.400020205

Colette J. Rudd

Papers

Deamidation of Glutaminyl and Asparaginyl Residues in Peptides and Proteins

Renaturation of disulfide‐linked procollagen