mot-c-peptide
Peptide oxidation is a chemical process where peptides undergo a reaction with oxygen or other oxidizing agents, leading to changes in their molecular structure and function. This degradation pathway is a significant concern across various fields, including pharmaceutical development, food science, and biological research, as it can impact the stability, efficacy, and quality of peptide-based products and biological systems. Understanding the mechanisms and consequences of peptide oxidation is crucial for developing strategies to mitigate its detrimental effects.
The primary sites for oxidation within a peptide molecule are specific amino acid residues. Methionine and cysteine are particularly susceptible due to their sulfur-containing side chains, which readily react with reactive oxygen species (ROS) and other oxidants. Cysteine residues can undergo reversible oxidation, forming disulfide bonds or sulfenic acids, while methionine typically oxidizes to methionine sulfoxide. Other amino acids like histidine, tryptophan, and tyrosine can also be targets for oxidation, leading to a variety of modified products.
Peptide oxidation can be triggered by various factors, both endogenous and exogenous. Reactive oxygen species (ROS), such as hydroxyl radicals, superoxide anions, and hydrogen peroxide, are common culprits.anhydrides of glycine and alanine [ ] 1 These are generated through normal metabolic processes, inflammation, or exposure to environmental stressors like radiation and certain chemicals.
Several conditions can accelerate peptide oxidation:
* pH: Higher pH levels can increase the susceptibility of certain residues, like cysteine, to oxidation.
* Temperature: Elevated temperatures often speed up chemical reactions, including oxidation.作者：I Karkossa·2023·被引用次数：5—...oxidationas well as reversibleoxidationof cysteines. Thus, we ... Afterpeptideclean-up,peptideswere eluted in two steps, first ...
* Presence of Metal Ions: Transition metal ions can catalyze the formation of ROS, thereby promoting oxidation.
* Light Exposure: Photodamage can generate reactive species that lead to peptide oxidation.
* Air and Other Oxidants: Exposure to atmospheric oxygen or specific oxidizing agents during synthesis, purification, formulation, or storage can induce oxidation.作者：R Torosantucci·2014·被引用次数：246—Abstract.Oxidationis a common degradation pathway that affects therapeutic proteins andpeptidesduring production, purification, formulation, ...
* Liquid-Solid Contact: Processes involving droplet drying on solid surfaces can also trigger analyte oxidationAmino Acid Oxidation Products.
The specific mechanisms of oxidation can vary. For instance, hydroxyl radicals can attack various amino acid side chains, leading to a range of fragmentation and modification products. The addition of oxygen atoms to susceptible amino acids is a hallmark of this process.
The impact of peptide oxidation extends to a peptide's biological activity, structural integrity, and overall quality.
* Loss of Biological Activity: Oxidative modifications can alter the peptide's three-dimensional conformation, affecting its ability to bind to target receptors or enzymes. This can lead to a significant reduction or complete loss of therapeutic efficacy for peptide-based drugs4天前—... peptides due to hydroxyl radicals using a low dose rate X-ray source. Keywords: hydroxyl radical footprinting. ;.peptide oxidation. ;. X-ray .... For example, methionine oxidation can reduce binding affinity to lipid bilayers by disrupting intrapeptide interactions.
* Altered Nutritional and Sensory Properties: In food science, peptide oxidation can negatively affect the nutritional value, taste, and texture of food products, particularly processed meats.
* Aggregation: Oxidized peptides may have a greater tendency to aggregate, which can have implications for drug formulation and delivery, as well as cellular function.
* Immunogenicity: Modified peptides can sometimes elicit an unwanted immune response, a critical consideration for therapeutic peptides.作者：YW Lao·2015·被引用次数：38—Methionineoxidationis one of the most frequently observed post-translational modifications ofpeptide/proteins, and may constitute up to 10% of the total non- ...
* Analytical Challenges: Oxidative modifications can complicate the analysis of peptides, for instance, affecting their chromatographic behavior作者：R Torosantucci·2014·被引用次数：246—Abstract.Oxidationis a common degradation pathway that affects therapeutic proteins andpeptidesduring production, purification, formulation, ....
Accurate detection and effective prevention of peptide oxidation are vital. Analytical techniques such as liquid chromatography-tandem mass spectrometry (LC-MS/MS) are employed for peptide mapping and characterization, allowing for the identification of oxidative modifications. Coulometric methods can be used for the quantitation of oxidizable peptides.
Preventive measures often involve careful control of storage and handling conditions. This includes:
* Minimizing Exposure to Oxygen: Storing peptides under inert atmospheres (e.作者：J Bergès·2011·被引用次数：35—Methionine and tyrosine are competing targets of oxidizing free radicals inpeptidesor proteins. The first step is the addition of OH radicals either on the ...g., nitrogen or argon) can help.
* Controlling Temperature: Refrigeration or freezing is commonly recommended.
* Using Antioxidants: Incorporating antioxidants into formulations can scavenge ROS作者：J Bergès·2011·被引用次数：35—Methionine and tyrosine are competing targets of oxidizing free radicals inpeptidesor proteins. The first step is the addition of OH radicals either on the ....
* Protecting from Light: Storing peptides in opaque containers.
* Optimizing pH: Maintaining a pH range that minimizes oxidation for specific residues.
* Chemical Strategies: For certain residues like methionine, strategies exist to reduce methionine sulfoxide back to native methionine, offering a way to reverse some oxidative damage.
In conclusion, peptide oxidation is a complex degradation process with far-reaching implicationsOxidation of peptides during electrospray ionization - Morand. By understanding the underlying mechanisms, identifying susceptible residues, and implementing appropriate handling and storage strategies, researchers and manufacturers can better preserve the integrity and functionality of peptides for various applications.
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