Table 1.
MALDI-MS analysis of E. coli proteolytic fragments generated by trypsin (Fig. 2). The identification of proteolytic fragments can occur even when m/z values are detected for intact proteins, as seen here for ribosomal protein L2. Protein fragments identified by asterisks, *, were still detected after 1500 min incubation with trypsin.
| Measured Mass [M+H]+ | Calculated Massa [M+H]+ | ΔM (Da) | Identity | Observed A.A. Residues | Loss of |
|---|---|---|---|---|---|
| 4738.2 | 4738.4 | -0.2 | L7/L12 | 75-121 | N-terminus |
| 4752.6 | 4752.4 | 0.2 | L7/L12 | 75-121 | N-terminus |
| 5270.9 | 5271.2 | -0.3 | L31* | 1-47 | C-terminus |
| 5461.6 | 5461.4 | 0.2 | L9* | 1-50 | C-terminus |
| 5555.1 | 5555.5 | -0.4 | L31* | 1-49 | C-terminus |
| 5617.3 | 5617.6 | -0.3 | L9* | 1-51 | C-terminus |
| 5761.3 | 5760.8 | 0.5 | S14 | 48-97 | N- and C-termini |
| 7128.4 | 7128.3 | 0.1 | L31 | 1-63 | C-terminus |
| 7315.7 | 7315.4 | 0.3 | S18* | 13-75 | N-terminus |
| 7339.1 | 7339.6 | -0.5 | L9 | 1-64 | C-terminus |
| 7721.5 | 7721.9 | -0.4 | S18 | 10-75 | N-terminus |
| 8162.6 | 8162.5 | 0.1 | S18 | 7-75 | N-terminus |
| 8357.9 | 8358.6 | -0.7 | L10* | 62-138 | N- and C-termini |
| 8529.9 | 8529.8 | 0.1 | L27* | 6-85 | N-terminus |
| 8629.1 | 8629.0 | 0.1 | S18 | 4-75 | N-terminus |
| 8658.1 | 8658.0 | 0.1 | L27 | 5-85 | N-terminus |
| 8768.8 | 8768.2 | 0.6 | S6 | 39-112 | N- and C-termini |
| 8870.7 | 8870.3 | 0.4 | S3 | 2-79 | C-terminus |
| 9715.9 | 9715.4 | 0.5 | S19* | 2-87 | C-terminus |
| 9844.9 | 9843.6 | 0.3 | S19* | 2-88 | C-terminus |
| 10043.6 | 10043.8 | -0.2 | S19 | 2-90 | C-terminus |
| 12310.6 | 12311.1 | -0.5 | S11* | 10-125/11-126/12-127/14-129 | N-and C-termini |
| 12248.5 | 12249.2 | 0.7 | L19* | 2-109 | C-terminus |
| 12566.1 | 12566.4 | -0.3 | S11 | 12-129 | N- and C-termini |
| 12861.2 | 12861.9 | -0.7 | S6 | 3-112 | N- and C-termini |
| 16225.1 | 16225.8 | -0.7 | S7 | 12-156 | N-terminus |
| 16895.1 | 16894.6 | 0.5 | S5* | 7-167 | N-terminus |
| 24842.3 | 24843.0 | -0.7 | S3* | 2-225 | C-terminus |
| 27597.6 | 27599.9 | -2.3 | L2* | 2-256 | C-terminus |
a
The average singly protonated mass of the tryptic products are shown as calculated using SequenceEditor ver. 1.0, provided by Bruker Daltonics and ProteinProspector.