Table 3.
Selected Rate Constants and Catalytic Efficiencies
| Reaction | Catalyst? | Rate constant or kcatapp/Kmappvalue | Reference |
|---|---|---|---|
| GSH + O2•− + H+→GS• + H2O2 | Nonenzymatic | ∼200 M−1s−1 | (142) |
| 2 O2•− + 2 H+→O2 + H2O2 | Nonenzymatic | 2 × 105M−1s−1 | (93) |
| 2 O2•− + 2 H+→O2 + H2O2 | Superoxide dismutase | 2 × 109M−1s−1 | (82) |
| GS• + NO•/NO2•/GS−→GSNO/NO2/SG•− | Nonenzymatic | ∼109M−1s−1 | (38, 147) |
| GSH + H2O2→GSOH + H2O | Nonenzymatic | 0.87 M−1s−1 | (295) |
| GSH + H2O2→GSOH + H2O | Ure2 | 84 M−1s−1 | (16) |
| GAPDHred + H2O2→GAPDHox + H2O | GAPDH | ∼(2–11) × 102M−1s−1 | (165) |
| Grxred + H2O2→Grxox + H2O | mGrx2 | 7.7 × 103M−1s−1 | (80) |
| Grxred + H2O2→Grxox + H2O | hGrx2 | 2.5 × 104M−1s−1 | (80) |
| Grxred + H2O2→Grxox + H2O | ScGrx1 | 5.3 × 104M−1s−1 | (52) |
| Grxred + H2O2→Grxox + H2O | ScGrx2 | 2.6 × 104M−1s−1 | (52) |
| Prxred + H2O2→Prxox + H2O | Tsa1 | 2.2 × 107M−1s−1 | (207) |
| Prxred + H2O2→Prxox + H2O | Tsa2 | 1.3 × 107M−1s−1 | (207) |
| GPxred + H2O2→GPxox + H2O | Mammalian GPx1/3 | (4–5) × 107M−1s−1 | (89, 273) |
| Prxred + H2O2→Prxox + H2O | Prx2 | 108M−1s−1 | (174) |
| GSH + HSA(SOH)→HSA(SSG) + H2O | Nonenzymatic | 2.9 M−1s−1 | (276) |
| Cys(SH) + Cys(SOH)→CysSSCys + H2O | Nonenzymatic | >105M−1s−1 | (199) |
| 2 GSH + GPx(SeOH)→GPx(SeH) + GSSG | Mammalian GPx1/3/4 | (0.6–4) × 105M−1s−1 | (273) |
| Trxred + GPx/Prx(SOH)→GPx/Prx(SH) + Trxox | Other GPx | ∼104−106M−1s−1 | (273) |
| LMW(SH) + RSSG→LMW(SSG) + RSH | Nonenzymatic | 0.01–200 M−1s−1 | (23, 198, 266) |
| Grx(SH) + Cys(SSG)→Grx(SSG) + Cys | hGrx1 | 7.0 × 105M−1s−1 | (96) |
| GSH + Grx(SSG)→Grx(SH) + GSSG | hGrx1 | 9.9 × 104M−1s−1 | (96) |
| Grx(SH) + Cys(SSG)→Grx(SSG) + Cys | hGrx2 | 1.0 × 105M−1s−1 | (96) |
| GSH + Grx(SSG)→Grx(SH) + GSSG | hGrx2 | 6.3 × 103M−1s−1 | (96) |
| Grx(SH) + BSA(SSG)→Grx(SSG) + BSA | PtGrxS12 | 8.0 × 105M−1s−1 | (300) |
| GSH + Grx(SSG)→Grx(SH) + GSSG | PtGrxS12 | 2.5 × 104M−1s−1 | (300) |
| Grx(SH) + GSSG→Grx(SSG) + GSH | SsGrx1 | 7.1 × 105M−1s−1 | (234) |
| Grx(SH) + Cys(SSG)→Grx(SSG) + Cys | ScGrx7 | (7.3–9.7) × 105M−1s−1 | (22) |
| GSH + Grx(SSG)→Grx(SH) + GSSG | ScGrx7 | (2.5–4.7) × 105M−1s−1 | (22) |
| Grx(SH) + Cys(SSG)→Grx(SSG) + Cys | PfGrxC32S/C88S | 1.4 × 106M−1s−1 | (22) |
| GSH + Grx(SSG)→Grx(SH) + GSSG | PfGrxC32S/C88S | 1.2 × 105M−1s−1 | (22) |
| Fd + Grx[2Fe2S2(GS)2]→Fd[2Fe2S2] + Grx +2 GSH | PtGrxS14 | 3.3 × 102M−1s−1 | (17) |