FIGURE 3.
Electrospray molecular-mass spectra. (A) The mass spectrum of denatured virions showing the four major coat proteins, CP1–4. (B) Expanded views of the regions around the major peaks for CP1–4. Potassium (K) adducts and oxidation products are indicated. Oxidation of cysteine, proline, methionine, or other residues in the protein may have occurred from storage of the virus sample, exposure to reagents, reaction with degraded β-mercaptoethanol in solution, or may be due to post-translational modifications.
