Table 1. Identified H. pylori outer membrane proteins differentially expressed following DHA treatment.
| No | Protein | MW (pI)§ | Protein score C.I.% | Mascot score | Distinct peptides | % coverage | Variation upon DHA; p value |
| 1 | Chaperone DnaK (HP0109) | 67.1 (5.0) | 100 | 356 | 37 | 55 | ↑1.6x; p<0.05 |
| 2 | Catalase (HP0875) | 58.7 (8.7) | 100 | 341 | 37 | 63 | ↓0.6x; p<0.05 |
| 3 | Urease accessory protein ureG (HP0068) | 22.1 (5.03) | 95 | 66 | 9 | 43 | ↑2.7x; p<0.05 |
| 4 | HP-NAP (HP0243) | 16.9 (5.6) | 100 | 156 | 16 | 75 | ↑2.5x; p<0.05 |
| 5 | Rod shape (HP1373) | 37.5 (5.4) | 100 | 183 | 21 | 55 | ↑2.2x; p<0.05 |
| 6 | |||||||
| Methionine aminopeptidase (HP1299) | 27.8 (6.0) | 99.9 | 85 | 11 | 41 | ↑2.0x; p<0.05 | |
| 7 | Methylhydantoinase (HP0696) | 87 (6.49) | 100 | 246 | 33 | 35 | ↓0.6x; p<0.05 |
| 8 | Heat shock protein A (HP 0011) | 12.9 (6.1) | 99.6 | 78 | 9 | 52 | ↑1.6x; p<0.05 |
| 9 | Ferritin (HP0653) | 19.3 (5.4) | 100 | 296 | 6 | 53 | ↑1.4x; p<0.05 |
| 10 | Urease accessory protein ureH (HP0067) | 30 (5.8) | 100 | 119 | 14 | 60 | ↑1.4x; p<0.05 |
| 11a* | γ-glutamyl-transpeptidase (HP1118) | 61 (9.3) | 100 | 167 | 11 | 15 | ↓0.51x; p<0.05 |
| 11b* | ATP-dependent protease HslV (HP0515) | 20 (6.5) | 99.9 | 97 | 3 | 19 | ↓0.51x; p<0.05 |
§
Molecular weight in kDa and pI in parentheses. Spot Mascot legend depicted in figure 5B .
*
Proteins 17a and 17b were identified from the same spot in the 2D-electrophoresis gel. Mascot score is defined as −10*Log10 (P), where P is the absolute probability. Protein score confidence interval (C.I.) % rates the confidence level of the Mascot Score to a 5% significance level. The closer the C.I.% is to 100%, the more likely the protein is correctly identified.
Twelve proteins identified by MALDI TOF/TOF mass spectrometry presented a differential expression level when comparing untreated control and DHA-treated bacteria. These proteins were mostly related with induction of stress condition.