Deamidationprone

Deamidationprone refers to amino acid residues within a protein sequence that are particularly susceptible to deamidation. Deamidation is a post-translational modification where the amide group of asparagine or glutamine residues is hydrolyzed, converting them into aspartic acid or glutamic acid, respectively. This modification can alter the protein's structure, function, and stability.

Certain sequence motifs are known to increase the propensity for deamidation. The most common and well-characterized is the Asn-Gly motif, where an asparagine followed by a glycine residue is highly prone to deamidation. Other susceptible residues or motifs include Asn-Ser, Asn-Thr, and Gln-Gly, though these are generally less reactive than the Asn-Gly pair. The proximity of these residues to the protein surface and their local chemical environment also play a role in their susceptibility.

The deamidation reaction is influenced by factors such as pH, temperature, and the presence of certain ions. Alkaline pH and elevated temperatures accelerate the process. The resulting aspartic or glutamic acid residues can lead to changes in charge, potentially affecting protein-protein interactions, enzyme activity, and susceptibility to further degradation. In some cases, deamidation can also trigger aspartimide formation, a cyclic intermediate that can lead to the isomerization of aspartic acid to isoaspartic acid, further impacting protein integrity. Understanding deamidationprone sites is crucial in protein engineering, biopharmaceutical development, and the study of protein aging and degradation.