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Analysis of thyroglobulin iodination by tandem mass spectrometry using immonium ions of monoiodo‐ and diiodo‐tyrosine
Author(s) -
Salek Mogjiborahman,
Lehmann Wolf D.
Publication year - 2005
Publication title -
proteomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.26
H-Index - 167
eISSN - 1615-9861
pISSN - 1615-9853
DOI - 10.1002/pmic.200400949
Subject(s) - chemistry , tyrosine , tandem mass spectrometry , thyroglobulin , mass spectrometry , halogenation , residue (chemistry) , peptide , dissociation (chemistry) , chromatography , ion , stereochemistry , medicinal chemistry , biochemistry , organic chemistry , endocrinology , biology , thyroid
Peptides containing a monoiodo‐ or diiodo‐tyrosine residue (monoiodo‐Y, diiodo‐Y) were found to generate abundant immonium ions following collision‐induced dissociation at m / z 261.97 and 387.87 Da, respectively. These residue‐specific marker ions are between about 140 mDa (monoiodo‐Y) and 300 mDa (diiodo‐Y) mass deficient relative to any other peptide fragment ions of unmodified peptides, qualifying them as highly specific marker ions for tyrosine iodination when analyzed by high resolution tandem mass spectrometry (MS/MS). Two new iodination sites (Y‐364 and Y‐2165) were pinpointed in bovine thyroglobulin by MS/MS using these iodotyrosine‐specific marker ions and combined tryptic/chymotryptic digestion.