Table 1.

Comparison of kinetic parameters and derived affinity constants for the binding of VACV B18 protein and derived mutants to heparin and hIFNα

Protein	Heparin binding			hIFNα binding
	Ka (M−1·s−1)	Kd (s−1)	KD (M)	Ka (M−1·s−1)	Kd (s−1)	KD (M)
VACV B18	5.7 × 105	2.18 × 10−3	3.83 × 10−9	3.89 × 105a	2.25 × 10−4a	5.8 × 10−10a
M15				1 × 106	2.22 × 10−4	2.21 × 10−10
M22				2.24 × 106	1.35 × 10−3	6.02 × 10−10

^aData from Fernández de Marco et al. (20).