ANYL 242 |
| Tyrosine-O-sulfation is a ubiquitous posttranslational modification in animal cells and it has been estimated that 1 in 3 of the proteins secreted by fibroblasts contains at least one sulfotyrosine residue. However, characterization of this posttranslational modification has been hampered for many years by the lack of a general, unambiguous method for its site-determination. This primarily results from its unique instability. We sought to address this question by using a ‘subtractive' strategy, in which we chemically label the non-sulfated tyrosine residues. In so doing, the information of the site of sulfation is encoded in the labeled tyrosines, which can be extracted using tandem MS experiments. This methodology was used to analyze a CCR8 N-terminal peptide modified in vitro by tyrosylprotein sulfotransferase, in which a series of ordered sulfation events were observed. In addition, this method was also used to locate the four and two sulfotyrosine residues in lumican and vitronectin, respectively. |
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Methods Development for Pharmaceutical Analysis
1:30 PM-5:00 PM, Tuesday, 12 September 2006 Moscone Center -- Room 124, Oral
Division of Analytical Chemistry |