oxidation of peptides summarizes the chemical mechanisms and detailed kinetics of amino acid and peptide oxidation - are-collagen-peptides-dairy-free summarizes the chemical mechanisms and detailed kinetics of amino acid and peptide oxidation Understanding the Oxidation of Peptides: Mechanisms, Consequences, and Mitigation

oxytocin-peptide-dosage-subcutaneous The oxidation of peptides is a critical area of study in biochemistry, pharmaceutical development, and analytical chemistry. It refers to the chemical process where peptides undergo a reaction involving the loss of electrons or the gain of oxygen atoms.2021年5月21日—In the supplementary material, a complete overview of alloxidation(Fig. S1) and chlorination events (Fig. S2) for allpeptidesin the library ... This process can significantly impact the structural integrity, function, and stability of peptides. Understanding the mechanisms, identifying susceptible residues, and developing strategies to prevent or manage peptide oxidation are paramount for various applications, from therapeutic drug development to fundamental research.Radiation-Chemical Oxidation of Peptides in the Solid State

Mechanisms and Susceptible Residues in Peptide Oxidation

Peptide oxidation primarily occurs through reactions with reactive oxygen species (ROS) and other oxidizing agents. Oxidizing free radicals in peptides, particularly hydroxyl radicals (•OH), are potent agents that can attack various amino acid residues.Identification of Peptide Oxidation by Tandem Mass ... Studies have shown that oxidation of some amino acids in the peptides has a direct impact on their structural properties and, consequently, their conformation.作者：N Borotto·2022·被引用次数：11—In this work, we demonstrate that when introduced into an electrospray ionization (ESI) source,ozone promotes the oxidation of proteins and peptides. This oxidative labeling is selective towards tryptophan and methionine residues. We also find that the labeling patterns are selective to pro- tein ...

Several amino acid residues are particularly susceptible to oxidation. These include:

* Methionine (Met): This sulfur-containing amino acid is readily oxidized to methionine sulfoxide. Methionine oxidation is a common concern, especially in peptides used therapeutically. Research has indicated that methionine oxidation reduces the affinity of Aβ binding to lipid bilayers by disrupting favorable intrapeptide interactions.作者：R Drozdź·1988·被引用次数：89—Oxidationwas studied of N-acetyl derivatives of cystine, cysteine, methionine and glycyltryptophan employing the myeloperoxidase-Cl--H2O2 system at pH 4.5, 6. ... Strategies to prevent methionine oxidation and reduce methionine sulfoxide back to native methionine are actively being investigated.

* Tryptophan (Trp): The indole ring of tryptophan is also prone to oxidation, leading to various oxidized products.作者：WM Garrison·1964·被引用次数：17—Gamma-ray irradiation of polypeptides as highly dispersed fluffs under oxygen leads to chemical degradation of thepeptidebond with the remarkably high ... Peptides and proteins carrying tyrosine (or tryptophan) can be electrochemically oxidized and subsequently analyzed using techniques like mass spectrometry.

* Tyrosine (Tyr): The phenolic ring of tyrosine can be oxidized, particularly by hydroxyl radicalsCysteine protecting groups: applications in peptide and ....

* Cysteine (Cys): The thiol side chain of cysteine is highly reactive and prone to side reactions like alkylation and oxidation. This is particularly relevant for disulfide-rich peptides.

* Histidine (His): The imidazole ring of histidine can also undergo oxidation.

The oxidation of a series of peptides containing Met and Pro residues has been investigated using techniques like gamma-radiolysis, highlighting the specific reactivity of these amino acids. Furthermore, ozone promotes the oxidation of proteins and peptides, with selective labeling observed for tryptophan and methionine residues. This oxidative labeling can be accelerated to submillisecond to second time scales, demonstrating the rapid nature of some oxidation processes.

Consequences of Peptide Oxidation

The consequences of peptide oxidation can be far-reaching:

* Structural Alterations: Oxidation can lead to changes in peptide conformation, affecting their three-dimensional structure and potentially their ability to interact with target moleculesOxidation of Amino Acids, Peptides, and Proteinssummarizes the chemical mechanisms and detailed kinetics of amino acid and peptide oxidationto help understand ....

* Functional Impairment: Altered structures can result in a loss or modification of biological activity. For instance, methionine oxidation reduces the affinity of Aβ binding, impacting its biological rolerapid-online-oxidation-of-proteins-and-peptides-via- ....

* Degradation: Oxidation is a common degradation pathway for peptides作者：R DrozdŹ·1988·被引用次数：89—Oxidationwas studied of N-acetyl derivatives of cystine, cysteine, methionine and glycyltryptophan employing the myeloperoxidase-Cl − -H 2 O 2 system at pH 4. .... It can lead to the cleavage of the peptide backbone, resulting in the release of fragments. This is a significant concern for the stability and shelf-life of peptide-based therapeutics. Oxidation of therapeutic proteins and peptides is a well-documented issue affecting their quality during production, purification, formulation, transportation, and storage.

* Immunogenicity: Modified peptides may be recognized as foreign by the immune system, potentially leading to adverse immune responses.

Detection and Analysis of Peptide Oxidation

Identifying and quantifying oxidized peptides is crucial for quality control and research.作者：P Zhao·2019·被引用次数：19—It has been reported thatpeptides and proteins carrying tyrosine (or tryptophan) can be electrochemically oxidizedand analyzed by MS [64,65,66] ... Various analytical techniques are employed:

* Mass Spectrometry (MS): Tandem mass spectrometry (MS/MS) is a powerful tool for the identification of peptide oxidation.作者：R DrozdŹ·1988·被引用次数：89—Oxidationwas studied of N-acetyl derivatives of cystine, cysteine, methionine and glycyltryptophan employing the myeloperoxidase-Cl − -H 2 O 2 system at pH 4. ... By analyzing mass shifts, specific oxidized residues can be pinpointed. Electrochemical oxidation and cleavage of peptides can be analyzed online using electrochemistry/electrospray mass spectrometry (EC/MS) systems作者：C Lockhart·2019·被引用次数：21—Methionine oxidation reduces the affinity of Aβ bindingto the DMPC bilayer by disrupting favorable intrapeptide interactions upon binding..

* Liquid Chromatography-Mass Spectrometry (LC-MS): This technique is widely used to monitor oxidation markers identified with LC-MSn, providing a comprehensive approach to peptide oxidation research.Absolute Quantitation of Oxidizable Peptides by Coulometric ...

* Coulometric Analysis: Absolute quantitation of oxidizable peptides by coulometric analysis offers a precise method for determining the extent of oxidation作者：RJ Spears·2021·被引用次数：114—The reactive nature of the thiol side chain makes it prone to side reactions such as alkylation andoxidation. Particularly for disulfide-rich ....

Managing and Mitigating Peptide Oxidation

Given the detrimental effects of oxidation, strategies to manage and mitigate it are essential:

* Protective Groups: In peptide synthesis, the use of cysteine protecting groups can prevent unwanted side reactions such as oxidation of the thiol side chainOxidation of Therapeutic Proteins and Peptides: Structural ....

* Controlled Storage Conditions: Maintaining peptides under controlled environments, such as low temperatures, inert atmospheres, and protection from light, can minimize oxidative degradation.作者：HP Permentier·2003·被引用次数：109—An on-line electrochemistry/electrospray mass spectrometry system (EC/MS) is described that allows fast analysis of theoxidationproducts ofpeptides.

* Antioxidants: Incorporating antioxidants into formulations can help scavenge reactive oxygen species and protect peptides from oxidation.

* Formulation Strategies: Optimizing the formulation of peptide-based products can enhance their stability against oxidation.

* Bioconjugation: While not directly preventing oxidation, bioconjugation reactions are critical to the modification of peptides and proteins, allowing for the introduction of probes or other functionalities that might indirectly influence stability or enable specific detection methods.

In conclusion, the oxidation of peptides is a multifaceted phenomenon with significant implications across various scientific disciplines. A deep understanding of its mechanisms, the identification of vulnerable amino acid residues like methionine, cysteine, histidine, tyrosine, and tryptophan, and the implementation of effective mitigation strategies are vital for ensuring the integrity, functionality, and therapeutic efficacy of peptides. The ongoing research into peptide oxidation continues to refine our understanding and develop more robust methods for handling and utilizing these essential biomolecules.