ANYL 7 |
| The most commonly used approach to obtain peptide sequence information from mass spectrometric analyses is collision activated dissociation (CAD) of cations, which produces sequence-specific b and y-type ions from peptide bond cleavage. However, for acidic peptides, negative ion mode operation is beneficial from a sensitivity stand-point. Unfortunately, CAD of peptide anions often generates a diversity of different bond cleavages, rendering such spectra difficult to interpret. Here, we will discuss the utility of anion-electron reactions for characterization of peptide primary structure. Electron irradiation (10-50 eV) of singly charged peptide anions provides complementary structural information compared to CAD, including some amino acid side chain losses. In addition, electron detachment dissociation (EDD) results in facile cleavage of disulfide bonds and peptide backbone cleavage without loss of phosphate for peptides containing a single serine phosphorylation. |
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Analytical Approaches
8:30 AM-12:00 PM, Sunday, 26 March 2006 Georgia World Congress Center -- B213, Oral
Sci-Mix
Division of Analytical Chemistry |