TABLE 2.
Mass spectrometric analyses of the SecY(I91pBpa) cross-linking products
A non-UV irradiated (not cross-linked, −UV) and a UV-irradiated (cross-linked, +UV) sample of SecY(I91pBpa) purified from whole cells was separated on 5–15% SDS gels and the proteins were visualized by Coomassie staining. The−UV and +UV lanes were cut into equal slices followed by in-gel trypsin digestion and mass spectrometry. Shown are the quantification for SecY, YidC, and the membrane-bound chaperone PpiD.
| Proteina | Molecular massb | Gel molecular massc | Relative intensity (−UV/+UV)d | Coveragee | Peptidesf |
|---|---|---|---|---|---|
| kDa | |||||
| YidC | 61.5 | 85 | 0.00 | 24.8 | 13 |
| PpiD | 68.1 | 103.6 | 0.00 | 66.5 | 32 |
| SecY | 48.5 | 85 | 0.04 | 23.5 | 11 |
| 105 | 0.02 | 18.3 | 8 | ||
| 115 | 0.26 | 16.7 | 7 | ||
a Protein identified.
b Calculated molecular mass.
c Molecular mass of gel slice determined by extrapolation.
d Relative intensity observed in gel slices from the control lane (−UV) compared to the +UV lane.
e Sequence coverage of total sequence by detected peptides.
f Number of peptides detected.