TABLE 3.
Methionine sulfoxide levels in SspC and SspCG52A oxidized in vivoa
| Protein | Treatment | % Methionine sulfoxide at residue:
|
|
|---|---|---|---|
| M27b | M67 | ||
| SspC | None | 3 (2) | 18 |
| tBHP | 10 (4) | 33 | |
| H2O2 | 12 (6) | 61 | |
| SspCG52A | None | 10 (5) | 25 |
| tBHP | 71 (50) | 94 | |
| H2O2 | 42 (28) | 84 | |
a
Spores of strains PS2437 (SspC) or PS2438 (SspCG52A) were treated and proteins were purified and analyzed as described in Materials and Methods.
b
Significant amounts of additional oxidation also occurred at lysine 28. This resulted in the production of a larger tryptic peptide (S9-R46), which was fully oxidized at M27. The amounts of this larger peptide have been included in calculations of M27 oxidation, and the percentage of oxidation at lysine 28 is given in parentheses.