. 2011 Apr 22;6(4):e17887. doi: 10.1371/journal.pone.0017887

Table 2. Thermodynamic parameters of Fab interactions with VEGF and HER2.

	ΔH_PBS	ΔH_Tris	ΔH^CORR	ΔS_TOT	ΔCp	ΔS_CONF	ΔS_SOLV	ΔS_RT
	kcal mol⁻¹	kcal mol⁻¹	kcal mol⁻¹	calK⁻¹ mol⁻¹	calK⁻¹ mol⁻¹	calK⁻¹ mol⁻¹	calK⁻¹ mol⁻¹	calK⁻¹ mol⁻¹
bH1-44/VEGF	−7.1	−8.0	−7.1	16	−400	−72	96	−8.0
bH1-44/HER2	−5.3	−3.1	−3.6	32	−440	−65	105	−8.0
Herceptin/HER2	−13.5	−8.0	−9.2	11	−370	−70	89	−8.0

ΔΗ_PBS and ΔΗ_Tris were determined by ITC in PBS (pH 7.4) or Tris (pH 7.5) buffer at 30°C.

ΔΗ^CORR, corrected ΔΗ, was calculated as described in Results.

ΔS_TOT, net total ΔS, was calculated from ΔΗ^CORR and ΔG as described in Methods.

ΔCp, heat capacity change, was calculated by linear regression of the temperature versus ΔH (Figure S6 and Methods). ΔCp of Herceptin/HER2 (−370 calK⁻¹ mol⁻¹+/−30 calK⁻¹ mol⁻¹) is based on [26]. Standard errors of ΔCp measurements for bH1-44/VEGF and bH1-44/HER2 interactions are 7 and 13 calK⁻¹ mol⁻¹, respectively.

ΔS_SOLV = ΔCpln(T/Ts*), where T = 303.15 K and Ts* = 385.15 K.

ΔS_RT was estimated to −8 cal K⁻¹ mol⁻¹ for a protein binding reaction.

ΔS_CONF was calculated as ΔS_CONF = ΔS_TOT−ΔS_SOLV−ΔS_RT, see Methods.

Standard errors of the ITC measurements were generally within 10% (See Figure 4).