TABLE 1.

Contributions from the attractive and repulsive force components to DNA condensation

The equilibrium interhelical spacings (± 0.1 Å) from direct x-ray measurements and repulsive and attractive force component contributions to osmotic pressures (± 5%) and free energies (± 5%) at 25 Å calculated from fits to force curves are shown for DNA condensed by various hexa-arginine peptides.

Peptide	Deq	ΠR(25 Å)/108 erg/cm3	−ΠA(25 Å)/108 erg/cm3	ΔGR(25 Å)/kT/base pair	−ΔGA(25 Å)/kT/base pair
	Å
R6	28.6	2.03	0.965	1.94	2.01
R3	30.15	1.68	0.54	1.61	1.12
Salmon protamine	29.26	3.02	1.33	2.89	2.35
R3A3R3	30.7	2.67	0.815	2.56	1.70
A3R6	30.0	2.535	0.89	2.43	1.85
R6A3	30.4	2.58	0.83	2.47	1.73
R3AR3	29.25	2.20	0.905	2.20	1.89
R3SR3	29.05	2.33	1.00	2.23	2.08
R3PR3	29.45	2.48	0.98	2.38	2.04
R3IR3	29.4	2.28	0.915	2.18	1.91
R3ER3	31.5	2.825	0.73	2.70	1.52
R3S(PO4−)R3	33.25	4.455	0.80	4.26	1.77