Table 3. The corresponding proteins were detected from seven spots by MALDI-TOF-MS/MS.
| Spot No. | Name | MW (kDa)/PI | Accession | Score | Mascot score |
|---|---|---|---|---|---|
| 1 | UCHL1 | 25,150.6/5.33 | UCHL1_HUMAN | 307 | 205 |
| 2 | CK19 | 44,079.1/5.04 | K1C19_HUMAN | 533 | 395 |
| 3 | CK19 | 44,079.1/5.04 | K1C19_HUMAN | 819 | 552 |
| 5 | CK19 | 44,079.1/5.04 | K1C19_HUMAN | 679 | 408 |
| 6 | CK8 | 53,671.1/5.52 | K2C8_HUMAN | 815 | 554 |
| 7 | ERO1L | 55,213.4/5.48 | ERO1A_HUMAN | 697 | 471 |
| 8 | PRDX2 | 22,049.3/5.66 | PRDX2_HUMAN | 379 | 285 |
Seven spots (spot no. 1, 2, 3, 5, 6, 7, and 8) were successfully detected in the preparative gels and excised for MALDI-TOF-MS/MS to identify the corresponding proteins. Spot no. 4 was not detected in the preparative gels. UCHL1 was the only protein expressed at least 4.5 times higher in A549 cells than in NCI-H358 cells. CK19, CK8, ERO1L, and PRDX2 were expressed at least 4.5 times higher in NCI-H358 cells than in A549 cells. MALDI-TOF-MS/MS, matrix-assisted laser desorption/ionization; PI, isoelectric point; UCHL1, ubiquitin carboxyl-terminal hydrolase isozyme L1; ERO1L, endoplasmic reticulum oxidoreductin 1-α; CK, cytokeratin; PRDX2, peroxiredoxin 2.