Table 2. The number of water involved in reactions.

Reaction	*	†
Hemoglobin: T → R‡	-65§	65 ± 4
Hemoglobin: T → R2‡	-22§	65 ± 4
Hemoglobin: T-LS → R‡	-23§	65 ± 4
Hemoglobin: T-LS → R2‡	20§	65 ± 4
P450cam → P450 + cam¶	7.6 ± 1.8∥	19**

^*Excess hydration number change calculated by using Eq. 14, based on the values tabulated in Table 1, and from high-pressure experiments. ΔV_E is the sum of ΔV_I (from Table 1) and thermal volume ΔV_T (35), where the empirical relation ΔV_T = δ × ΔSASA (δ = 1.0 Å for proteins and 0.56 Å for camphor) was used (18, 35). The units are mol/mol. The error bar was evaluated following Filfil and Chalikian (36).

^†From osmotic stress measurements. Hemoglobin by Colombo et al. (4) at 37°C and P450cam by Di Primo et al. (22) at 20°C.

^‡Candidates for the conformational changes upon hemoglobin's oxygen uptake.

^§ (19) is used. Assuming the error of ±5 ml/mol, the error bar to is no larger than ±4.

^¶Camphor release from camphor-bound cytochrome P450.

^∥ ml/mol (22) is used.

^**Error bar not given in ref. 22. It is expected to have accuracy similar to other data in the table.