Table 3. ITC derived thermodynamic parameters for the binding of polyamines to MLDNA^a.

Polyamines	Temperature (K)	Ka (×104 M−1)	N	ΔG o (kcal/mol)	ΔH o (kcal/mol)	TΔS o (kcal/mol)	ΔCp o (cal/mol K)
Spermine	283.15	6.52±0.02	0.714±0.004	−6.230±0.012	1.217±0.009	7.447±0.023	−24.5±0.02
	288.15	5.20±0.09	0.682±0.009	−6.223±0.021	1.096±0.011	7.319±0.015
	293.15	3.33±0.15	0.551±0.004	−6.060±0.013	0.972±0.012	7.032±0.013
Spermidine	283.15	4.55±0.03	0.646±0.011	−6.034±0.011	1.101±0.015	7.135±0.018	−21.2±0.01
	288.15	2.88±0.06	0.607±0.021	−5.890±0.013	0.997±0.012	6.887±0.015
	293.15	2.20±0.02	0.536±0.005	−5.821±0.020	0.889±0.009	6.710±0.019
Putrescine	283.15	3.49±0.01	0.617±0.004	−5.892±0.021	1.017±0.021	6.909±0.014	−15.1±0.05
	288.15	2.84±0.03	0.572±0.009	−5.877±0.010	0.952±0.019	6.829±0.011
	293.15	2.04±0.01	0.534±0.007	−5.781±0.009	0.866±0.014	6.651±0.007
Cadaverine	283.15	3.79±0.02	0.727±0.017	−5.923±0.012	1.014±0.013	6.937±0.011	−13.7±0.03
	288.15	2.87±0.02	0.595±0.017	−5.889±0.018	0.940±0.030	6.829±0.016
	293.15	2.02±0.06	0.531±0.015	−5.716±0.021	0.877±0.008	6.593±0.011

^aAll the data in this table are derived from ITC experiments conducted in 20 mM [Na⁺] citrate-phosphate buffer, pH 7.0 and are average of four determinations, K_a and ΔH ^o values were determined from ITC profiles fitting to Origin 7 software as described in the text. The values of ΔG ^o and TΔS ^o were determined using the equation ΔG ^o = −RTlnK_a, and TΔS ^o = ΔH ^o−ΔG ^o. All the ITC were fit to a model of single binding sites.