Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0032290 (aspiration pneumonia)
 2,291 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

During the time course of disulfide bond formation by iodine oxidation (in a methanolic and hydrochloric acid solution) of a cysteinyl(S-acetamidomethyl)-glutaminyl tridecapeptide, we observed by ESI, FAB mass spectrometry (pseudo-molecular ion and ion-fragments) and 1H-NMR a side reaction due to a shift of the Acm leaving group from cysteine to the carboxamide side chain of glutamine. This type of Acm-shift at low level was described previously by L.W. Mendelson et al. (Int. J. Pept. Protein Res. 35:249-257) for an aspariginyl-cysteinyl(S-acetamidomethyl) peptide in an anhydrous hydrochloric solution. We report here the efficiency of glutamine as a scavenger to suppress the S-->N shift of the acetamidomethyl group during S-acetamidomethyl cleavage and sulfhydryl oxidation with iodine, as the folded tridecapeptide was obtained with the expected molecular weight.
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PMID:Side reaction of S-to-N acetamidomethyl shift during disulfide bond formation by iodine oxidation of S-acetamidomethyl-cysteine in a glutamine-containing peptide. 883 14