α1S fluorescent protein construct conductance and intramembrane charge movement
| Construct | G-V | Q-V | Gmax/Q′ | ||||
| Gmax | V1/2 | kG | Qmax | VQ | kQ | ||
| nS/nF | mV | mV | nC/μF | mV | mV | nS/pC | |
| α1S-YFPa | 140 ± 5 (37) | 31.2 ± 0.8 | 8.1 ± 0.2 | 6.0 ± 0.4 (8) | −3.2 ± 2.0 | 9.0 ± 0.7 | 33 |
| α1S(671-CFP-YFP) + (686)α1S | 174 ± 13 (20) | 36.0 ± 0.9 | 7.4 ± 0.3 | 4.2 ± 0.8 (7) | −9.5 ± 4.5 | 9.2 ± 0.6 | 54 |
| α1S(671) + (CFP-YFP-686)α1S | 144 ± 13 (20) | 35.5 ± 1.1 | 7.8 ± 0.3 | 3.5 ± 1.4 (4) | −11.1 ± 6.6 | 9.3 ± 1.4 | 58 |
| α1S(671-CFP) + (YFP-686)α1S | 164 ± 15 (18) | 36.0 ± 1.1 | 7.4 ± 0.4 | 4.4 ± 1.1 (5) | −4.8 ± 5.4 | 5.3 ± 2.6 | 48 |
| α1S(671-CFP-YFP-686) | 182 ± 11 (33) | 33.9 ± 1.1 | 7.3 ± 0.3 | 6.3 ± 0.8 (7) | −3.1 ± 0.8 | 11.3 ± 0.7 | 34 |
| α1S(726-CFP-YFP-727) | 67 ± 5 (30)b | 38.5 ± 1.8d | 10.4 ± 0.7b | 5.4 ± 0.9 (6) | −12.2 ± 4.1d | 11.7 ± 1.4 | 15 |
| α1S(726-YFP-727) | 116 ± 11 (15)b | 35.1 ± 2.2 | 9.7 ± 0.7b | 6.9 ± 0.6 (6) | −12.1 ± 1.4b | 13.4 ± 0.9 | 20 |
| α1S(760-YFP-761) | 102 ± 10 (12)b | 34.1 ± 0.9 | 9.2 ± 0.7c | 8.0 ± 1.6 (5) | −7.6 ± 1.8c | 14.0 ± 1.4 | 15 |
| α1S(785-YFP-786) | 72 ± 10 (12)b | 38.9 ± 3.4 | 9.5 ± 1.7 | 5.2 ± 0.8 (5) | −11.3 ± 4.8 | 12.5 ± 1.0 | 17 |
| Uninjected dysgenic myotubes | no inward current (17) | no inward current (17) | no inward current (17) | 1.0 ± 0.2 (6) | −5.0 ± 4.6 | 9.6 ± 3.0 | ND |
| Construct | G-V | Q-V | Gmax/Q′ | ||||
| Gmax | V1/2 | kG | Qmax | VQ | kQ | ||
| nS/nF | mV | mV | nC/μF | mV | mV | nS/pC | |
| α1S-YFPa | 140 ± 5 (37) | 31.2 ± 0.8 | 8.1 ± 0.2 | 6.0 ± 0.4 (8) | −3.2 ± 2.0 | 9.0 ± 0.7 | 33 |
| α1S(671-CFP-YFP) + (686)α1S | 174 ± 13 (20) | 36.0 ± 0.9 | 7.4 ± 0.3 | 4.2 ± 0.8 (7) | −9.5 ± 4.5 | 9.2 ± 0.6 | 54 |
| α1S(671) + (CFP-YFP-686)α1S | 144 ± 13 (20) | 35.5 ± 1.1 | 7.8 ± 0.3 | 3.5 ± 1.4 (4) | −11.1 ± 6.6 | 9.3 ± 1.4 | 58 |
| α1S(671-CFP) + (YFP-686)α1S | 164 ± 15 (18) | 36.0 ± 1.1 | 7.4 ± 0.4 | 4.4 ± 1.1 (5) | −4.8 ± 5.4 | 5.3 ± 2.6 | 48 |
| α1S(671-CFP-YFP-686) | 182 ± 11 (33) | 33.9 ± 1.1 | 7.3 ± 0.3 | 6.3 ± 0.8 (7) | −3.1 ± 0.8 | 11.3 ± 0.7 | 34 |
| α1S(726-CFP-YFP-727) | 67 ± 5 (30)b | 38.5 ± 1.8d | 10.4 ± 0.7b | 5.4 ± 0.9 (6) | −12.2 ± 4.1d | 11.7 ± 1.4 | 15 |
| α1S(726-YFP-727) | 116 ± 11 (15)b | 35.1 ± 2.2 | 9.7 ± 0.7b | 6.9 ± 0.6 (6) | −12.1 ± 1.4b | 13.4 ± 0.9 | 20 |
| α1S(760-YFP-761) | 102 ± 10 (12)b | 34.1 ± 0.9 | 9.2 ± 0.7c | 8.0 ± 1.6 (5) | −7.6 ± 1.8c | 14.0 ± 1.4 | 15 |
| α1S(785-YFP-786) | 72 ± 10 (12)b | 38.9 ± 3.4 | 9.5 ± 1.7 | 5.2 ± 0.8 (5) | −11.3 ± 4.8 | 12.5 ± 1.0 | 17 |
| Uninjected dysgenic myotubes | no inward current (17) | no inward current (17) | no inward current (17) | 1.0 ± 0.2 (6) | −5.0 ± 4.6 | 9.6 ± 3.0 | ND |
Data are given as mean ± SEM, with the numbers in parentheses indicating the number of myotubes tested. See Materials and methods for fits. For all of the data given, the calculated average voltage error was <5 mV. Significant differences between α1S(671-CFP-YFP-686) and the other individual one-piece constructs (i.e., α1S(726-CFP-YFP-727), α1S(726-YFP-727), α1S(760-YFP-761), and α1S(785-YFP-786)) are indicated.
α1S-YFP data from Bannister and Beam (2005) are included for comparison.
P < 0.001 by t test.
P < 0.01 by t test.
P < 0.05 by t test.