TABLE 1.
Comparison of molecular masses calculated from sequences and observed by mass spectrometrya
| Wk | Predicted molecular mass (Da) (cloning frequency) | Observed molecular mass (Da) |
|---|---|---|
| 52 | 7,101.5 (50/50) A | 7,102.85 ± 1.60 A |
| 54 | 7,101.5 (12/22) A | 7,103.33 ± 0.90 A |
| 7,107.5 (3/22) B | 7,075.26 ± 3.33 C | |
| 7,080.5 (2/22) | ||
| 7,073.5 (2/22) C | ||
| 7,101.5 (2/22) | ||
| 7,165.6 (1/22) | ||
| 55 | 7,107.5 (4/19) B | 7,106.98 ± 2.77 B |
| 7,080.5 (3/19) | 7,082.17 ± 5.68 E | |
| 7,165.6 (3/19) D | 7,166.30 ± 2.38 D | |
| 7,110.5 (3/19) | 7,048.26 ± 5.03 F | |
| 7,085.5 (3/19) E | ||
| 7,101.5 (1/19) | ||
| 7,103.5 (1/19) | ||
| 7,062.5 (1/19) | ||
| 56 | 7,107.5 (6/11) B | 7,107.14 ± 2.08 B |
| 7,080.5 (2/11) | 7,083.99 ± 3.39 E | |
| 7,085.5 (1/11) E | 7,167.75 ± 0.98 D | |
| 7,043.4 (1/11) F | ||
| 7,165.6 (1/11) D | ||
| 59 | ND | 7,111.46 ± 2.58 |
| 7,085.44 ± 2.99 E | ||
| 7,047.31 ± 3.98 F | ||
| 7,168.73 ± 2.03 D |
a
For the calculation of molecular masses, the amino acid sequence in Fig. 1 was used as well as the amino acid sequence encoded by the primers; posttranslational modifications were taken into account. For details, see reference 1. For the observed masses, three measurements were taken. Results are given as means ± standard deviations. Tentative associations between clones identified by the two methods are indicated by the same letter, taking into account the precision of the MALDI-TOF method (1) and the clone frequency. ND, not done.