Table 1:
Kinetic Parameters of Mutant and Wild-Type Thymidine Kinases
HSV TK
A168Y
A168F
Thymidine
K
m
(µM)
1.06
a
1.18
1.70
k
cat
(s
-1
)
40.30
0.83
51.00
k
cat
/K
m
(s
-1
/µM)
38.02
0.70
30.00
Ganciclovir
K
m
(μM)
45.50
45.80
8.60
k
cat
(s
-1
)
55.30
6.00
91.10
k
cat
/K
m
(s
-1
/µM)
1.22
0.13
10.59
Relative Specificity
b
0.03
0.16
0.26
a
Values are the averages of at least three independent measurements. Standard error of the means are within a range of ± 20%.
b
Relative Specificity = (k
cat
/K
m (GCV)
)/((k
cat
/K
m (GCV)
) + (k
cat
/K
m (dT)
)).