TABLE 1.
Properties of FRET-based maltose sensors with different linkers and binding sites
| Maltose sensor | 530/480 fluorescence intensity ratioa
|
Change in ratiob | Kd value ± SD (μM)c | |
|---|---|---|---|---|
| Without maltose | With maltose | |||
| CMY-0 | 1.56 | 1.61 | 0.05 | 2.4 ± 0.2 |
| CMY-B | 1.35 | 1.35 | ||
| CMY-BII | 1.85 | 2.02 | 0.17 | 1.8 ± 0.1 |
| CMY-QI | 1.96 | 2.30 | 0.34 | 1.8 ± 0.1 |
| CMY-LH | 3.02 | 3.52 | 0.50 | 1.6 ± 0.1 |
| CMY-LH/W62H | 2.92 | 3.61 | 0.69 | 40 ± 1 |
| CMY-LH/W62L | 2.66 | 3.66 | 1.00 | 80 ± 1 |
| CMY-LH/W62A | 2.70 | 3.00 | 0.30 | 255 ± 6 |
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 maltose.
c
The Kd value ± standard deviation of the concentration (μM) of maltose that induces a half-maximal increase in the intensity ratio.