Biomedical Engineering Reference
In-Depth Information
Baronian and Gurazada (2007
) have recently analyzed the electrochemical detection of wild-
type
S. cerevisiae
responses to estrogens. They point out that the presence of an EBP and an
endogeneous ligand in three yeast species was first reported in the early 1990s. This ligand
was 17
b
-estradiol, and the binding affinity of this protein with a variety of estrogen and
estrogen-like molecules has been noted for
S. cerevisiae
(
Burshell et al., 1984
),
Candida
albicans
(
Madani et al., 1994
), and
Paracoccidioides brasiliensis
.
Baronian and Gurazada
(2007)
indicate that the relative binding affinities of
S. cerevisiae
and
C. albicans
EBPs
are similar for 17
b
-estradiol, estradiol, estrone, estriol, and 17
a
-estradiol.
Figure 13.5a
shows the binding of EBP in
Saccharomyces cerevisiae
. A single-fractal anal-
ysis is adequate to describe the binding kinetics. The values of the binding rate coefficient
k
and the fractal dimension
D
f
for a single-fractal analysis are given in
Table 13.5
.
Figure 13.5b
shows the binding of 1.1 nM 17
b
-estradiol. Once again, a single-fractal analysis
is adequate to describe the binding kinetics. The values of the binding rate coefficient
k
and
the fractal dimension
D
f
for a single-fractal analysis are given in
Table 13.5
.
It is of interest to note that as the fractal dimension increases by a factor of 1.29 from a
value of 1.6944 for the wild-type case to 2.1904 for the 11 nM 17
b
-estradiol case, the
binding rate coefficient increases by 1.37% (a very slight increase) from a value of
k
equalto159.24to
k
equal to 161.42. Note that change in the fractal dimension or the
degree of heterogeneity on the electrochemical surface and in the binding rate coefficient
are in the same direction.
Ma et al. (2007)
have reported that restriction endonucleases are important enzymes in
molecular biology. They are involved in recombinant technology, mapping, genotyping and
400
300
250
300
200
200
150
100
100
50
0
0
0
1
2
3
4
0
1
2
Time (h)
3
4
B
Figure 13.5
(a) Binding of EBP (estrogen binding protein) in Saccharomyces cerevisiae. (b) Binding of 1.1 nM
17
A
Time (h)
-estradiol (
Baronian and Guruzada, 2007
).
b
