Biomedical Engineering Reference
In-Depth Information
Table 9.7: Binding and dissociation rate coefficients for calcium to a FRET-based calcium
biosensor employing troponin C as a calcium-binding moiety (
Mank et al., 2006
).
Calcium/Troponin C Based
Calcium Biosensor Stimulation
Frequency (Hz)
k
k
1
k
2
k
d
1.5 mM external calcium;160 Hz
for 2.2 s
47.167
2.994 51.736
2.435
48.642
1.147 71.562
10.229
1.5 mM external calcium; 80 Hz
for 2.2 s
23.762
2.876 25.515
3.623
30.2
0.0
34.191
5.136
1.5 mM external calcium; 40 Hz
for 2.2 s
8.293
1.326 10.458
0.075
7.808
0.029 11.633
2.063
10 mM external calcium; 160 Hz
for 2.2 s
56.591 9.545 74.569 12.857 59.148 1.224 97.878 54.11
TN-XL (biosensor) fluorescence changes in Drosophila in vivo.
Table 9.8: Fractal dimensions for the binding and the dissociation phase for calcium
to a FRET-based calcium biosensor employing troponin C as a calcium-binding moiety
(
Mank et al., 2006
).
Calcium/Troponin C
Based Calcium Biosensor
Stimulation Frequency
(Hz)
D
f
D
f1
D
f2
D
fd
1.5 mM external calcium;
160 Hz for 2.2 s
2.4844
0.0612
2.2534
0.09186 2.6754
0.1093
1.5324
0.1374
1.5 mM external calcium;
80 Hz for 2.2 s
2.0796
0.0812
1.9644
0.1328
3.0
0.0
1.7234
0.1627
1.5 mM external calcium;
40 Hz for 2.2 s
2.2062
0.07384 1.6144
0.01372 2.2976
0.0278
1.6948
0.2412
10 mM external calcium;
160 Hz for 2.2 s
2.3482 0.1159
1.9486 0.2280
2.8129 0.03394
0 þ 0.5116
TN-XL (biosensor) fluorescence changes in Drosophila in vivo.
It is of interest to note that for a dual-fractal analysis as the fractal dimension increases by a
factor of 1.187 from a value of
D
f1
equal to 2.2534 to
D
f2
equal to 2.6754, the binding rate
coefficient decreases by a factor of 1.06 from a value of
k
1
equal to 51.736 to
k
2
equal to
48.642. In this case, and this is rare, an increase in the degree of heterogeneity or the fractal
dimension on the biosensor surface leads to a decrease in the binding rate coefficient.
þ
Figure 9.7b
shows the binding and the dissociation phases for the 1.5 mM calcium
FRET-
based calcium biosensor employing troponin C (
Mank et al., 2006
). The external stimulation
frequency was 80 Hz for 2.2 s. Once again, a dual-fractal analysis is required to adequately
describe the kinetics in the binding phase. A single-fractal analysis is adequate to describe the
