Table 2.
MALDI-TOF mass spectrometry of rLytN-digested dimeric peptidoglycan fragments
| Compound1 |
m/z2 |
Δ (observed and calculated) | Predicted structure | |
|---|---|---|---|---|
| Observed | Calculated | |||
| pitet + Buffer | ||||
| i | 2416.57† | 2415.67 | 0.90 | (NAG-NAM)-AQK(G5)A-(NAG-NAM)-AQK(G5)AA |
| pitet-fmhC + Buffer | ||||
| i | 2446.53† | 2445.70 | 0.83 | (NAG-NAM)-AQK(G5)A-(NAG-NAM)-AQK(G4S1)AA |
| i | 2476.55† | 2475.74 | 0.81 | (NAG-NAM)-AQK(G4S1)A-(NAG-NAM)-AQK(G4S1)AA |
| pitet + rLytN | ||||
| ii | 1275.50 | 1275.42 | 0.08 | (NAG-NAM)-AQK(G5)AA |
| ii | 1233.49 | 1234.42 | 0.07 | (NAG-NAM)-AQK(G4S1)A |
| iii | 1204.49 | 1204.33 | 0.16 | (NAG-NAM)-AQK(G5)A |
| iii | 1162.48 | 1161.28 | 1.20 | (NAG-NAM)-AQK(G3)AA |
| iv | 1261.51 | 1261.40 | 0.11 | (NAG-NAM)-AQK(G5)A(G1) |
| iv | 1001.45 | 1001.12 | 0.33 | (NAM)-AQK(G5)A |
| pitet-fmhC + rLytN | ||||
| ii | 1275.50 | 1275.42 | 0.08 | (NAG-NAM)-AQK(G5)AA |
| iii | 1234.50 | 1234.42 | 0.08 | (NAG-NAM)-AQK(G4S1)A |
| iii | 1204.49 | 1204.33 | 0.16 | (NAG-NAM)-AQK(G5)A |
1See Fig. 3C for compounds i.e. absorption peaks of reverse-phase HPLC of mutanolysin-treated S. aureus peptidoglycan.
2Observed and calculated m/z values are for sodiated ions recorded in reflectron-positive mode, with the exception of † which were analyzed reflectron negative mode and therefore are [−H+].