Table 2. Oxidative modifications identified by LC-MS/MS on the recombinant sPPase protein p26a after H2O2 treatment.
Oxidative modifications identified on the recombinant protein p26a and its phosphomimic mutant p26a(3E) and phosphonull mutant p26a(3A) without and after H2O2 treatment. Bold text indicates irreversible oxPTMs. I, Irreversible; R, reversible. Details of oxidative modifications relating to these experimental data are in Supplemental Tables S8, S9, S10, and S11 and Supplemental Figure S2.
| Residue | Untreated | H2O2-Treated | ||
|---|---|---|---|---|
| p26a | p26a(3E) | p26a(3A) | ||
| C99 | – | – | Cysteic acid (I) | Cysteic acid (I) |
| M111 | – | – | Met sulfone (I) | Met sulfoxide (R) Met sulfone (I) |
| C119 | – | – | Cysteic acid (I) Nitrosyl (R) | – |
| M129 | Met sulfoxide (R) | Met sulfoxide (R) | Met sulfoxide (R) | Met sulfoxide (R) |
| M131 | – | – | Met sulfoxide (R) | Met sulfoxide (R) |
| C145 | – | – | – | Sulfinic acid |
| M202 | – | – | Met sulfoxide (R) Met sulfone (I) | Met sulfoxide (R) |
| M210 | Met sulfoxide (R) | – | Met sulfoxide (R) | Met sulfoxide (R) |
| M211 | Met sulfoxide (R) | – | Met sulfoxide (R) | Met sulfoxide (R) |