Table 3. Binding Constants for TGF-β Ligands to the Signaling Receptors.

surface	analyte	buffer suppl	kon (M–1 s–1)	koff (s–1)	Kd (μM)	Rmax (RU)
TGF-β1	TβRII	none	7.2(±0.4) × 105	0.121(±0.007)	0.17 ± 0.01	53.6 ± 4.3
TGF-β3	TβRII	none	1.2(±0.1) × 106	0.199(±0.009)	0.17 ± 0.01	79.2 ± 4.0
TGF-β131	TβRII	none	5.5(±0.1) × 105	0.124(±0.002)	0.22 ± 0.01	41.3 ± 1.0
TGF-β313	TβRII	none	1.4(±0.1) × 106	0.171(±0.003)	0.13 ± 0.01	64.5 ± 3.2
TGF-β3H4	TβRII	none	5.1(±0.2) × 105	0.083(±0.002)	0.16 ± 0.01	67.0 ± 3.2
TGF-β1	TβRI	4 μM TβRII	3.3(±0.1) × 104	7.6(±0.4)x ×	0.24 ± 0.01	27.6 ± 1.4
TGF-β3	TβRI	4 μM TβRII	3.5(±0.1) × 104	1.2(±0.1) × 10–3	0.034 ± 0.002	59.3 ± 3.0
TGF-β131	TβRI	4 μM TβRII	5.2(±0.1) × 104	2.6(±0.1) × 10–3	0.051 ± 0.001	27.4 ± 1.4
TGF-β313	TβRI	4 μM TβRII	5.4(±0.1) × 104	5.1(±0.2) × 10–2	0.95 ± 0.04	56.5 ± 2.9
TGF-β3H4	TβRI	4 μM TβRII	4.0(±0.1) × 104	1.9(±0.4) × 10–3	0.047 ± 0.003	56.4 ± 3.0