TABLE 1.

Summary of biophysical constants of protein-protein interactions

N.D. indicates not detected.

Interaction	ITC					SPR
	ΔG	ΔH	−TΔS	Stoichiometry	Kd	kon	koff	Kd	χ2 (U value)
	kcal/mol	kcal/mol	kcal/mol			m−1 s−1	s−1	nm
SinI-SinR	−11.9	−8.36 ± 0.16	−3.58a	1.27 ± 0.01	≤10 nm	2.73 ± 0.01 × 104	5 ± 0.06 × 10−5	1.83	0.12 (5)
SlrA-SinR	−10.9	−7.89 ± 0.44	−2.97a	0.89 ± 0.02	≤10 nm	2.16 ± 0.01 × 104	2.3 ± 0.006 × 10−4	10.6	40.8 (1)
SlrR-SinR	N.D.	N.D.	N.D.	N.D.	N.D.	4.85 ± 0.03 × 103	2.3 ± 0.015 × 10−4	47.5	0.10 (NA)
SinR-Inverted repeat DNA	−8.77	4.33 ± 0.12	−13.12	2.38 ± 0.05	360 ± 122 nm	1 × 105b	2 × 10−2b	270 ± 50	N.D.
SinR-Single site DNA	−6.68	−5.78 ± 0.11	0.90	1.07 ± 0.01	12.5 ± 1.2 μm	N.D.	N.D.	N.D.	N.D.
SinR-Tandem site DNA	−6.18	1.66 ± 0.13	−7.84	∼2	30 ± 7 μm	N.D.	N.D.	N.D.	N.D.

^a K_d measured by SPR was used for fitting ITC data to obtain ΔS.

^b Values estimated by simulation software from data of Colledge et al. (11).