Table 3.

Kinetics and affinity constants for RGD-hirudin and mutant variant binding to thrombin

Variant analyzed	Association rate k a (M −1  s −1 )	Dissociation rate k d (s −1 )	Binding affinity K D (M)
RGD-hirudin	1.77 × 103	2.73 × 10−5	1.55 × 10−8
Y3A	0.80	2.88 × 10−3	3.61 × 10−3
S50A	1.12 × 103	3.94 × 10−5	3.50 × 10−8
Q53A	59.20	3.37 × 10−5	5.70 × 10−7
D55A	371.00	3.83 × 10−4	1.03 × 10−6
Q57A	155.00	3.74 × 10−4	2.41 × 10−6
I59A	73.00	1.39 × 10−3	1.90 × 10−5