Chemical Instability of Proteins

• peptide bonds can break the polymer chain

  Hydrolysis
• These reactions convert neutral amino acid residues into charged ones


  Deamidation
• this type of base-catalyzed reactions can occur in any of the amino acids except glycine, which is achiral.


  Racemization
• occurs following the abstraction of the -hydrogen from the amino acid to form a carbanion

  Racemization
• Proteins containing Cys, Ser, Thr, Phe, and Lys

  B-Elimination
• occur at the sulfur-containing amino acids Met and Cys and at the aromatic amino acids His, Trp, and Tyr.

  Oxidation