TABLE 2.
Signal intensity and dynamic range for FRET-based sucrose/maltose sensors with different linkers
| Sensor | 530/480 fluorescence intensity ratioa
|
Change in ratiob | Kd value ± SD (μM)c | |
|---|---|---|---|---|
| Without substrate | With substrate | |||
| CSY-B | ||||
| Sucrose | 1.56 | 1.45 | −0.11 | 286 ± 16 |
| Maltose | 1.55 | 1.45 | −0.10 | 1,132 ± 183 |
| CSY-BII | ||||
| Sucrose | 1.64 | 1.78 | 0.14 | 234 ± 18 |
| Maltose | 1.65 | 1.79 | 0.14 | 773 ± 69 |
| CSY-LH | ||||
| Sucrose | 1.83 | 2.55 | 0.72 | 163 ± 3 |
| Maltose | 1.83 | 2.57 | 0.74 | 640 ± 21 |
a
Intensity ratio between fluorescence emissions at 530 nm and at 480 nm when sensor proteins were excited at 436 nm.
b
Maximum change of the 530/480 ratio in response to substrate.
c
The Kd value ± standard deviation of the concentration (μM) of substrate that induces a half-maximal increase in the intensity ratio.