TABLE 1.
Positive ion MALDI-TOF MS analysis of H. pylori wild type muropeptides
|
Muropeptidea
|
Peak no.
|
Observed
ionb
|
||
|---|---|---|---|---|
| Before N-acetylation | After N-acetylation | Mass difference | ||
| 894 | ||||
| 965 | ||||
| 979 | ||||
| 1 | 993 | 1078 | 42 × 2 = 2 acetyl groups | |
| 2 | 1015 | 1098 | 42 × 2 = 2 acetyl groups | |
| 1021 | ||||
| Tetra-G-G | 1036 | |||
| 1052 | ||||
| 3 | 1196 | 1238 | 42 × 1 = 1 acetyl groups | |
| 4 | 1399 | 1483 | 42 × 2 = 2 acetyl groups | |
| 5 | 1713 | 1756 | 42 × 1 = 1 acetyl groups | |
| 6 | 1896 | 1980 | 42 × 2 = 2 acetyl groups | |
| 1917 | ||||
| Tetra-G-G-tetra | 1937 | |||
| 1955 | ||||
| 7 | 2009 | 2093 | 42 × 2 = 2 acetyl groups | |
| 8 | 2026 | 2111 | 42 × 2 = 2 acetyl groups | |
a
Tetra = disaccharide-tetrapeptide (Ala-Glu-Lys-Ala); disaccharide = GlcNAc-MurNAc, reduced with sodium borodeuteride; G = Gly; assignments represent the most likely fit based on typical amino acid components.
b
Ions are present as the sodiated molecular species, [M + Na]+1, rounded to nearest whole mass.