IANBD-cTnCT53C fluorescence lifetime changes upon myosin release from rigor with ATP in low Ca2+
| Experiment (N) . | Buffer condition . | Buffer condition . | Average lifetime . | SD . | C.V. . | n . | Change + ATP . | Z′ . | P . |
|---|---|---|---|---|---|---|---|---|---|
| #1 | Rigor | Low Ca2+ | 2.61 | 0.01 | 0.4% | 23 | |||
| ATP | Low Ca2+ | 2.53 | 0.01 | 0.5% | 23 | −3.2% | 0.16 | 7.2 × 10−27 | |
| #2 | Rigor | Low Ca2+ | 2.67 | 0.02 | 0.7% | 23 | |||
| ATP | Low Ca2+ | 2.61 | 0.01 | 0.5% | 23 | −2.5% | −0.41 | 4.1 × 10−18 | |
| #3 | Rigor | Low Ca2+ | 2.69 | 0.01 | 0.5% | 24 | |||
| ATP | Low Ca2+ | 2.56 | 0.02 | 0.7% | 24 | −4.8% | 0.22 | 1.6 × 10−29 | |
| #4 | Rigor | Low Ca2+ | 2.54 | 0.01 | 0.5% | 11 | |||
| ATP | Low Ca2+ | 2.41 | 0.01 | 0.4% | 11 | −5.2% | 0.49 | 2.4 × 10−17 | |
| Average | Rigor | Low Ca2+ | − | − | − | ||||
| ATP | Low Ca2+ | − | − | − | −3.9% | 0.11 | 7.0 × 10−18 |
| Experiment (N) . | Buffer condition . | Buffer condition . | Average lifetime . | SD . | C.V. . | n . | Change + ATP . | Z′ . | P . |
|---|---|---|---|---|---|---|---|---|---|
| #1 | Rigor | Low Ca2+ | 2.61 | 0.01 | 0.4% | 23 | |||
| ATP | Low Ca2+ | 2.53 | 0.01 | 0.5% | 23 | −3.2% | 0.16 | 7.2 × 10−27 | |
| #2 | Rigor | Low Ca2+ | 2.67 | 0.02 | 0.7% | 23 | |||
| ATP | Low Ca2+ | 2.61 | 0.01 | 0.5% | 23 | −2.5% | −0.41 | 4.1 × 10−18 | |
| #3 | Rigor | Low Ca2+ | 2.69 | 0.01 | 0.5% | 24 | |||
| ATP | Low Ca2+ | 2.56 | 0.02 | 0.7% | 24 | −4.8% | 0.22 | 1.6 × 10−29 | |
| #4 | Rigor | Low Ca2+ | 2.54 | 0.01 | 0.5% | 11 | |||
| ATP | Low Ca2+ | 2.41 | 0.01 | 0.4% | 11 | −5.2% | 0.49 | 2.4 × 10−17 | |
| Average | Rigor | Low Ca2+ | − | − | − | ||||
| ATP | Low Ca2+ | − | − | − | −3.9% | 0.11 | 7.0 × 10−18 |
Average data are provided for individual experiments. Experiments were carried out with three separate protein preparations of troponin that was exchanged into four separate myofibril preparations. Low Ca2+ is pCa 9. The unit for Average (fluorescence) lifetime and SD is nanoseconds (ns). n = number of wells of myofibrils (in rigor buffer) into which low Ca2+ or low Ca2+ plus ATP is individually added and scanned at 20 min. Change + ATP is the percentage change in lifetime between low Ca2+ without nucleotide and low Ca2+ + ATP for each experiment. C.V. is the coefficient of variance. Statistical tests of Z′ factor and t test are used to evaluate the change in lifetime between addition of equal volumes of rigor buffer and ATP in low Ca2+. The average Z′ and percentage Change + ATP for the four experiments is also given.