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. 2004 Mar;13(3):830–841. doi: 10.1110/ps.03330104

Figure 3.

Figure 3.

Scan-rate dependence of the apparent van’t Hoff enthalpy (ΔHv,app). Plots of ΔHv,app vs. the reciprocal of the scan rate (1/v) for NAD+ synthetase unfolding without (open circles) and with (solid circles) DMSO. (Open circles) NAD+ synthetase (~1 mg/mL) in 60 mM EPPS (pH 8.5) with 20 mM KCl, 19 mM NH4Cl, 10 mM MgCl2. Data fitting used the two-state dissociative model. The extrapolated ΔHv value at infinite scan rate is 953 (±17) kJ/mole. The rightmost point was excluded from the linear regression. (Solid circles) NAD+ synthetase in 60 mM EPPS (pH 8.5) with 20 mM KCl, 19 mM NH4Cl, 10 mM MgCl2, 2.5% DMSO. Data fitting used the sequential three-state fit model. The extrapolated ΔHv for unfolding (Equilibrium 2; see Materials and Methods for details) at infinite scan rate was 487(±10) kJ/mole. The calculated total ΔHv for both equilibria is 1151 (±17) kJ/mole (see Table 2).