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Methionine oxidation (revision 2)

Old revision·10:26, 11 Nov 2024·ColumnOvenCoy

This is an old revision of this page, as it stood at 10:26, 11 Nov 2024, saved by ColumnOvenCoy with the summary rm the claim that the method is stability-indicating without a forced-degradation study. It may differ substantially from the current revision, and any error it contains may since have been corrected.
Methionine oxidation
Residue affectedMethionine; cysteine and tryptophan by related routes
Mass change+16 Da (sulfoxide); +32 Da (sulfone)
Promoted byPeroxides, trace metals, light, dissolved oxygen
Topic infobox · conventions

Methionine oxidation converts the thioether side chain of methionine to a sulfoxide, adding 16 daltons, and on further oxidation to a sulfone, adding 32. It is one of the most common oxidative degradation routes in peptides and is readily detected by mass spectrometry because the mass shift is large.[1]

Oxidation is promoted by dissolved oxygen, by trace transition metals, by peroxide impurities in excipients, and by light. Unlike deamidation, which proceeds spontaneously in clean aqueous solution, oxidation generally requires an oxidant, and controlling the oxidant is therefore an effective control strategy.[2]

References

  1. ^ Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS. "Stability of protein pharmaceuticals: an update." Pharmaceutical Research 27(4):544–575 (2010). PMID 20143256.
  2. ^ United States Pharmacopeia, General Chapter <1503>, Quality Attributes of Synthetic Peptide Drug Substances.