Table II. Calculated and observed protein masses of complex I subunits from P. pastoris and their corresponding post-translational modifications.
| Subunit | Mass |
Δ mass | ppm | Modifications | |
|---|---|---|---|---|---|
| Calc. | Obs. | ||||
| 1. NUAM/75 kDa1 | 76746.3 | 76760.6 | 14.3 | 186.0 | ΔImport(1–24) |
| 2. NUBM/51 kDa1 | 50852.3 | 50867.3 | 15.0 | 295.0 | ΔImport(1–11) |
| 3. NUCM/49 kDa1 | 51347.5 | 51382.9 (3.4) | 35.4 | 689.4 | ΔImport(1–31) |
| 4. NUGM/30 kDa2 | 29046.9 | 29048.3 (1.6) | 1.4 | 48.2 | ΔImport(1–38) |
| 5. NUHM/24 kDa1 | 24344.0 | 24349.6 | 5.6 | 230.0 | ΔImport(1–26) |
| 6. NUIM/TYKY | – | – | – | – | – |
| 7. NUKM/PSST | – | – | – | – | – |
| 8. NU1M/ND13 | 39681.3 | 39717.3 (16.3) | 36.0 | 907.2 | N-α-Formyl |
| 9. NU2M/ND23 | 59074.7 | 59086.1 | 11.4 | 193.0 | N-α-Formyl |
| 10. NU3M/ND33 | 16011.0 | 16014.8 (7.4) | 3.8 | 237.3 | N-α-Formyl |
| 11. NU4M/ND43 | 54756.9 | 54773.2 (8.7) | 16.3 | 297.7 | N-α-Formyl |
| 12. NU5M/ND53 | 72396.9 | – | – | – | – |
| 13. NU6M/ND63 | 18561.6 | 18561.6 (1.3) | 0.0 | 0.0 | N-α-Formyl |
| 14. NULM/ND4L3 | 9116.9 | 9117.0 (0.3) | 0.1 | 11.0 | N-α-Formyl |
| 15. NUEM/39 kDa1 | 42356.0 | 42358.8 (1.9) | 2.8 | 66.1 | ΔImport(1–7) |
| 16. NESM/ESSS2 | 24577.2 | 24579.5 (9.8) | 2.3 | 93.6 | ΔImport(1–24) |
| 17. NUJM/B14.72 | 23393.6 | 23394.1 (1.3) | 0.5 | 21.4 | -Met, N-α-Acetyl |
| 18. NUXM2 | 22254.2 | 22255.2 (1.4) | 1.0 | 44.9 | N-α-Acetyl |
| 19. NUPM/PGIV1,4 | 20704.5 | 20697.4 | 7.1 | 343.0 | -Met, N-α-Acetyl |
| 20. NUZM2 | 20057.0 | 20058.4 | 1.4 | 69.8 | -Met |
| 20099.0 | 20100.4 | 1.4 | 69.7 | -Met, N-α-Acetyl | |
| 21. NUSM2 | 17987.8 | 17988.6 (1.6) | 0.8 | 44.5 | ΔImport(1–28) |
| 22. NIMM/MWFE2 | 17418.7 | 17419.3 (1.0) | 0.6 | 34.4 | none |
| 23. NB6M/B16.61 | 17191.7 | 17192.2 (1.3) | 0.5 | 29.1 | -Met |
| 17233.7 | 17234.6 | 0.9 | 52.2 | -Met, N-α-Acetyl | |
| 24. N7BM/B17.23 | 16323.4 | 16323.4 | 0.0 | 0.0 | -Met, N-α-Acetyl |
| 25. NUYM/18 kDa3 | 15994.0 | 15995.4 (1.9) | 1.4 | 87.5 | ΔImport(1–20) |
| 26. NIAM/ASHI2 | 15226.1 | 15226.6 (0.8) | 0.5 | 32.8 | ΔImport(1–24) |
| 27. NUMM/13 kDa2 | 14339.2 | 14338.0 (0.8) | −1.2 | −83.7 | ΔImport(1–11) |
| 28. NUFM/B132 | 14531.6 | 14533.2 (1.0) | 1.6 | 110.1 | ΔImport(1–8) |
| 29. NB4M/B141 | 14628.8 | 14629.4 | 0.6 | 41.0 | -Met |
| 30. NI2M/B222 | 12733.6 | 12735.0 (1.2) | 1.4 | 109.9 | -Met, N-α-Acetyl |
| 31. NIPM/15 kDa1 | 12097.8 | 12094.4 | −3.4 | −282.5 | -Met |
| 32. ACPM1/SDAP13 | 10659.6 | 10656.4 (0.1) | −3.1 | −290.9 | ΔImport(1–46) + PP5 |
| 33. NIDM/PDSW1 | 10639.9 | 10637.4 (1.5) | −2.5 | −235.0 | -Met, S23L6 |
| 34. NI8M/B82 | 9860.5 | 9861.4 (0.5) | 0.9 | 91.3 | -Met, N-α-Acetyl |
| 35. ACPM2/SDAP2 | 10032.0 | – | – | – | ΔImport(1–42) + PP5 |
| 36. NB8M/B183,4 | 10323.9 | 10320.1 (1.0) | 3.8 | 368.2 | -Met |
| 37. NUTM2 | 9721.2 | 9721.3 (0.7) | 0.2 | 20.5 | -Met |
| 38. NB5M/B152 | 9291.6 | 9292.1 (0.6) | 0.5 | 53.8 | -Met |
| 39. NI9M/B92 | 9037.4 | 9038.3 (0.7) | 0.9 | 99.6 | -Met |
| 40. NUUM3 | 8192.3 | 8192.4 | 0.1 | 12.2 | -Met |
| 41. NB2M/B123 | 6996.8 | 6997.7 (1.4) | 0.9 | 128.6 | -Met, S49L6 |
Calculated masses include the modifications specified. Observed masses are mean averages for masses measured more than once, and standard deviations are given in brackets for masses observed more than twice.
- Assigned by indirect correlation of a protein mass with tryptic peptide data from a duplicate sample.
- Assigned by direct correlation of a protein mass with tryptic peptide data from the same sample.
- Assigned only by correlation of a measured mass with a predicted candidate mass.
- The mass discrepancies for subunits NUPM/PGIV and NB8M/B18 may be due to the formation of protein disulfides.
- PP, pantetheine-4′-phosphate.
- Amino acid substitution identified by tandem MS (see Table S1).