Table IV. (Rp)-cAMPS effects on amide H/2H exchange in the C-subunit complexed to RIα(91–244).
Non-overlapping 95% confidence intervals relative to control values were determined by the Prizm computer program.
| Fragment of C-subunit (m/z) (region) | Number of exchangeable amides | Charge (z) | Maximum amides exchanged (mean ± S.E.)a |
|
|---|---|---|---|---|
| Control | Plus (Rp)-cAMPS | |||
| 7–18 (700.32) (αA) | 11 | 2 | 8.2 ± 0.05 | 9.7 ± 0.19 |
| 14–31 (732.72) (αA) | 17 | 3 | 4.3 ± 0.11 | 5.3 ± 0.11 |
| 19–26 (461.25) (αA) | 7 | 2 | 4.2 ± 0.10 | 5.3 ± 0.37 |
| 19–27 (534.79) (αA) | 8 | 2 | 4.4 ± 0.13 | 4.9 ± 0.18 |
| 21–36 (953.5) (αA-β1) | 14 | 2 | 8.4 ± 0.19 | 9.5 ± 0.22 |
| 27–40 (822.44) (αA-β1) | 12 | 2 | 7.7 ± 0.17 | 8.3 ± 0.20 |
| 28–40 (765.90) (αA-β1) | 11 | 2 | 7.6 ± 0.12 | 8.2 ± 0.19 |
| 42–55 (792.90) (β1) | 13 | 2 | 1.9 ± 0.07 | 2.0 ± 0.13 |
| 45–55 (597.83) (β1) | 10 | 2 | 3.0 ± 0.11 | 3.0 ± 0.14 |
| 60–71 (700.84) (β1-β2) | 11 | 2 | 0.4 ± 0.02 | 0.9 ± 0.04 |
| 83–100 (727.74) (αB-αC) | 17 | 3 | 3.3 ± 0.09 | 3.2 ± 0.13 |
| 92–100 (544.83) (αC) | 8 | 2 | 1.7 ± 0.06 | 1.6 ± 0.09 |
| 98–103 (736.403) (αC) | 4 | 1 | 0.9 ± 0.02 | 0.8 ± 0.04 |
| 98–104 (807.44) (αC) | 5 | 1 | 1.6 ± 0.03 | 1.6 ± 0.09 |
| 104–108 (635.38) (β4) | 4 | 1 | Solvent-inaccessible | Solvent-inaccessible |
| 104–110 (869.48) (β4) | 6 | 1 | 1.0 ± 0.02 | 1.2 ± 0.07 |
| 105–110 (770.41) (β4) | 5 | 1 | 1.0 ± 0.05 | 1.1 ± 0.08 |
| 106–115 (1200.55) (β4) | 9 | 1 | 1.7 ± 0.06 | 1.7 ± 0.11 |
| 109–116 (924.44) (β4) | 7 | 1 | 1.0 ± 0.02 | 1.1 ± 0.06 |
| 119–126 (825.38) (β5) | 7 | 1 | 0.2 ± 0.02 | 0.4 ± 0.02 |
| 122–128 (726.32) (β5-αD) | 6 | 1 | 1.0 ± 0.17 | 0.8 ± 0.08 |
| 122–129 (855.36) (β5-αD) | 7 | 1 | 1.0 ± 0.14 | 1.0 ± 0.29 |
| 133–145 (570.29) (αD-αE) | 12 | 3 | 1.2 ± 0.03 | 1.3 ± 0.01 |
| 144–151 (470.26) (αE) | 7 | 2 | 3.0 ± 0.10 | 2.9 ± 0.03 |
| 156–163 (989.49) (αE-β6) | 7 | 1 | 0.3 ± 0.02 | 0.3 ± 0.01 |
| 162–173 (743.94) (β6-β7) | 10 | 2 | 0.5 ± 0.04 | 0.3 ± 0.3 |
| 173–178 (673.35) (β7) | 5 | 1 | 1.3 ± 0.01 | 0.9 ± 0.05 |
| 180–185 (722.36) (β8) | 5 | 1 | 0.3 ± 0.24 | 0.2 ± 0.19 |
| 180–187 (926.46) (β8) | 7 | 1 | Solvent-inaccessible | Solvent-inaccessible |
| 182–187 (685.32) (β8) | 5 | 1 | Solvent-inaccessible | Solvent-inaccessible |
| 188–212 (981.52) (β9-activation loop) | 22 | 3 | 3.5 ± 0.08 | 3.5 ± 0.08 |
| 189–212(932.50) (β9-activation loop) | 21 | 3 | 3.3 ± 0.08 | 3.2 ± 0.09 |
| 198–211 (1418.73) (β9-activation loop) | 10 | 1 | Solvent-inaccessible | Solvent-inaccessible |
| 205–211 (768.49) | 5 | 1 | Solvent-inaccessible | Solvent-inaccessible |
| 222–227 (658.40) (αF) | 5 | 1 | Solvent-inaccessible | Solvent-inaccessible |
| 231–245 (826.90) (αF-αG) | 11 | 2 | 5.3 ± 0.12 | 5.0 ± 0.19 |
| 232–239 (869.43) (αF) | 5 | 1 | 1.1 ± 0.03 | 1.2 ± 0.02 |
| 241–247 (784.42) (αF-αG) | 5 | 1 | 3.0 ± 0.10 | 2.9 ± 0.27 |
| 262–269 (890.48) (αH) | 7 | 1 | Solvent-inaccessible | Solvent-inaccessible |
| 262–273 (693.90) (αH) | 11 | 2 | Solvent-inaccessible | Solvent-inaccessible |
| 268–273 (741.50) (αH) | 5 | 1 | Solvent-inaccessible | Solvent-inaccessible |
| 268–274 (869.56) (αH) | 6 | 1 | Solvent-inaccessible | Solvent-inaccessible |
| 278–302(748.40) (αH-αI) | 24 | 4 | 7.0 ± 0.20 | 8.1 ± 0.20 |
| 291–303 (831.41) (αH-αI) | 12 | 2 | 3.1 ± 0.16 | 3.3 ± 0.22 |
| 298–303 (740.33) (αH-αI) | 5 | 1 | 2.4 ± 0.08 | 2.6 ± 0.15 |
| 303–326(669.87) (C-terminal tail) | 19 | 4 | 9.5 ± 0.12 | 9.9 ± 0.20 |
| 303–327(706.64) (C-terminal tail) | 20 | 4 | 9.0 ± 0.17 | 9.4 ± 0.17 |
| 305–327(623.85) (C-terminal tail) | 18 | 4 | 10.0 ± 0.13 | 10.5 ± 0.25 |
| 306–327 (632.34) (C-terminal tail) | 17 | 4 | 8.1 ± 0.06 | 8.5 ± 0.13 |
| 335–346 (728.36) (C-terminal tail) | 11 | 2 | 7.0 ± 0.10 | 7.9 ± 0.11 |
a Average number of deuterons exchanged determined from fitting plots of the time course of deuteration during a 10-min exposure to deuterium oxide to a single exponential equation. Values reported are the mean and S.E. of the amplitude term of fits, and results are from at least two independent experiments. All deuterium exchange values reported were corrected for a 32.7% back-exchange by multiplying the centroid values by a multiplication factor of 1.49. Peptides showing significant differences upon (Rp)-cAMPS binding are in bold.