Table I.

Streptavidin Association and Dissociation Rates

Wild-type SA	kon (M−1 sec−1)	koff (sec−1)	Kd (M)	Ref.
Biotin*	6.7 × 107 ± 7 × 104	4.4 × 10−6 ± 5.5 × 10−7	6.5 × 10−14 ± 8.2 × 10−15	2
Biotin T10*	8.5 × 107 ± 8 × 106	1.1 × 10−6 ± 1.3 × 10−7	1.3 × 10−14 ± 1.9 × 10−15	10
Desthiobiotin	2.7 × 107 ± 6.4 × 104	1.8 × 10−2 ± 4.9 × 10−3	6.6 × 10−10 ± 1.8 × 10−10
Desthiobiotin T10*	5.1 × 106 ± 9.3 × 105	4.4 × 10−4 ± 3 × 10−5	8.2 × 10−11 ± 1.7 × 10−11	10
R4–6 SA
Biotin	2.5 × 107 ± 1.2 × 104	ND	ND
Biotin T10*	ND	7.7 × 10−5 ± 5.5 × 10−6	ND	10
Desthiobiotin	2.8 × 107 ± 2.5 × 104	1.2 × 10−2 ± 4 × 10−3	4.3 × 10−10 ± 1 × 10−10
Desthiobiotin T10*	4.0 × 107 ± 3 × 104	9.4 × 10−5 ± 8.3 × 10−6	2.3 × 10−12 ± 2 × 10−13	10
R7–2 SA
Biotin*	5.5 × 106 ± 1.2 × 105	7.5 × 10−4 ± 3.3 × 10−5	1.4 × 10−10 ± 6.7 × 10−12	10
Biotin T10*	1.3 × 107 ± 1.4 × 104	1.5 × 10−5 ± 8.3 × 10−7	1.2 × 10−12 ± 6.3 × 10−14	10
Desthiobiotin	7.1 × 106 ± 2.4 × 104	3.5 × 10−3 ± 6 × 10−4	4.9 × 10−10 ± 8.5 × 10−11
Desthiobiotin T10*	1.3 × 107 ± 6.1 × 104	1.4 × 10−5 ± 1.6 × 10−6	1.0 × 10−12 ± 1.2 × 10−13	10

^*Dissociation rates obtained from the literature.