Table 3. Kinetic parameters for the interactions between streptavidin variants and the SBP ligands.

Streptavidin	Binding partner	On-rate (M -1 s -1 )	Off-rate (s -1 )	K d (M)
wtSAV	BLA-L-SBP	1.26 x 105	6.03 x 10−4	4.79 x 10−9
SAVSBPM18	BLA-L-SBP	3.32 x 104	3.41 x 10−4	1.03 x 10−8
SAVSBPM32	BLA-L-SBP	3.14 x 104	3.17 x 10−4	1.01 x 10−8
SAVSBPM18	BLA-L-SBP(A18C)	3.58 x 104	3.30 x 10−3	9.20 x 10−8
SAVSBPM18	Biotinylated BSA	1.01 x 105	5.72 x 10−4	5.66 x 10−9
SAVSBPM32	Biotinylated BSA	4.12 x 104	5.56 x 10−4	1.35 x 10−8