Table II. Time-resolved anisotropy decay parameters of FM-R92C, FM-T104C, and FM-R239C RIα(91–244) mutants free and complexed to the C-subunit in absence and presence of cAMP, (Rp)-cAMPS, or (Sp)-cAMPS.
The concentrations of the FM-RIα(91–244)conjugates, C-subunit, and cyclic nucleotides were 0.4, 4, and 100 μm, respectively.
| Mutant state | Condition | β1a | β2b | φfastc | φslowd | χr2e | 〈τ〉 |
|---|---|---|---|---|---|---|---|
| FM-R92C | |||||||
| Holo | Control | 0.080 ± 0.002 | 0.176 ± 0.015 | 1.5 ± 0.1 | 38 | 1.6 | 2.6 ± 0.1 |
| Holo | cAMP | 0.082 ± 0.001 | 0.198 ± 0.015 | 1.5 ± 0.2 | 38 | 1.6 | 2.7 ± 0.1 |
| Holo | (Rp)-cAMPS | 0.078 ± 0.003 | 0.180 ± 0.010 | 1.6 ± 0.1 | 38 | 1.5 | 2.6 ± 0.1 |
| Holo | (Sp)-cAMPS | 0.076 ± 0.002 | 0.190 ± 0.007 | 1.7 ± 0.1 | 38 | 1.5 | 2.7 ± 0.1 |
| Apo | Control | 0.089 ± 0.011 | 0.130 ± 0.007 | 0.9 ± 0.1 | 7.6 ± 1.1 | 1.6 | 3.6 ± 0.1 |
| Apo | cAMP | 0.087 ± 0.016 | 0.132 ± 0.001 | 0.9 ± 0.1 | 7.5 ± 1.8 | 1.5 | 3.6 ± 0.1 |
| Apo | (Rp)-cAMPS | 0.088 ± 0.005 | 0.133 ± 0.005 | 0.9 ± 0.1 | 7.1 ± 0.4 | 1.4 | 3.6 ± 0.1 |
| Apo | (Sp)-cAMPS | 0.081 ± 0.002 | 0.132 ± 0.005 | 0.9 ± 0.1 | 7.1 ± 0.1 | 1.9 | 3.6 ± 0.1 |
| FM-T104C | |||||||
| Holo | Control | 0.040 ± 0.002 | 0.241 ± 0.014 | 3.0 ± 0.6 | 38 | 1.4 | 3.5 ± 0.1 |
| Holo | cAMP | 0.031 ± 0.004 | 0.199 ± 0.018 | 3.8 ± 0.3 | 38 | 1.5 | 3.7 ± 0.3 |
| Holo | (Rp)-cAMPS | 0.041 ± 0.004 | 0.237 ± 0.013 | 2.9 ± 0.3 | 38 | 1.5 | 3.5 ± 0.1 |
| Holo | (Sp)-cAMPS | 0.047 ± 0.002 | 0.194 ± 0.016 | 3.2 ± 0.2 | 38 | 1.6 | 3.5 ± 0.1 |
| Apo | Control | 0.096 ± 0.010 | 0.154 ± 0.004 | 2.1 ± 0.1 | 11.0 ± 2.2 | 1.4 | 3.6 ± 0.3 |
| Apo | cAMP | 0.092 ± 0.019 | 0.165 ± 0.007 | 2.1 ± 0.3 | 10.7 ± 3.2 | 1.5 | 3.7 ± 0.2 |
| Apo | (Rp)-cAMPS | 0.091 ± 0.006 | 0.153 ± 0.017 | 1.9 ± 0.1 | 9.8 ± 1.0 | 1.4 | 3.6 ± 0.1 |
| Apo | (Sp)-cAMPS | 0.097 ± 0.009 | 0.152 ± 0.008 | 2.1 ± 0.1 | 10.8 ± 2.2 | 1.5 | 3.6 ± 0.1 |
| FM-R239C | |||||||
| Holo | Control | 0.052 ± 0.003 | 0.215 ± 0.006 | 1.7 ± 0.1 | 38 | 1.2 | 3.6 ± 0.1 |
| Holo | cAMP | 0.057 ± 0.004 | 0.203 ± 0.013 | 2.3 ± 0.2 | 38 | 1.2 | 3.5 ± 0.1 |
| Holo | (Rp)-cAMPS | 0.053 ± 0.002 | 0.197 ± 0.010 | 1.7 ± 0.2 | 38 | 1.2 | 3.6 ± 0.1 |
| Holo | (Sp)-cAMPS | 0.054 ± 0.002 | 0.196 ± 0.008 | 2.3 ± 0.3 | 38 | 1.2 | 3.5 ± 0.1 |
| Apo | Control | 0.081 ± 0.001 | 0.173 ± 0.008 | 2.4 ± 0.3 | 13.1 ± 1.2 | 1.5 | 3.3 ± 0.3 |
| Apo | cAMP | 0.068 ± 0.002 | 0.175 ± 0.004 | 1.6 ± 0.1 | 10.2 ± 0.6 | 1.4 | 3.3 ± 0.2 |
| Apo | (Rp)-cAMPS | 0.073 ± 0.011 | 0.167 ± 0.004 | 2.0 ± 0.2 | 11.0 ± 2.5 | 1.4 | 3.3 ± 0.1 |
| Apo | (Sp)-cAMPS | 0.065 ± 0.005 | 0.168 ± .006 | 1.7 ± 0.1 | 9.4 ± 0.7 | 1.5 | 3.3 ± 0.1 |
a Amplitude of the fast anisotropy decay processes.
b Amplitude of the slow anisotropy decay processes.
c Rotational correlation time of fast anisotropy decay processes.
d Rotational correlation time of slow anisotropy decay processes.
e Reduced χr2 of the anisotropy decay analysis.