Biomedical Engineering Reference
In-Depth Information
vivo. Cells are either selected or rejected on the basis of photokinetic properties of genet-
ically altered purple membrane. Cells that are selected in the initial screen, as illustrated
in Figure 14.4b, are subjected to further selection processes, including protein expression
and branched photochemistry [60].
These techniques have been employed frequently for optimization of proteins and
enzymes used in industrial processes. In such cases, directed evolution is used to enhance
1119T, A126S
(a)
max
(nm)
580
WT
575
570
565
560
555
l108T, l117N
550
P77Q, 178F
178F
A110P, G113
545
l117N
540
120
State decay time (ms)
State formation time (ms)
100
80
l108R
l119T,
T121S,
A126T
60
P77Q, 178F
40
20
0
0
l119T, T121S, A126T
Q
1
0.12
∞
[O]d
t
t
=
τ
−
1
t
=0
0.10
Q
=
P77R, Y79F, L87M
0.08
l108L, L111F
0.06
0.04
0.02
0.00
0
20
40
60
80
100
Well number
(b)
Controller
electronics
Controller
electronics
Controller
electronics
Drop controller
Drop controller
Drop controller
CCD
CCD
BS
BS
BS
FL
FL
GR
GR
GR
CCD
FL
HSDS
HSDS
HSDS
(1)
(3)
(2)
Selected
high
Q
tot
Selected
potential
high
Q
tot
Deselected
denatured
or low
Q bR
quantum
efficiency
Selected
stable
mutation
with high
growth
rate
Deselected
poor folding
or thermal
instability
Deselected
low
Q
tot
96WP
