Figure 2.

Temperature and pH dependencies of H2, H3 H6 and H1 proton chemical shifts (δ₂, δ₃, δ₆ and δ₁) of TmDOTP⁵⁻ are shown in (A), (B), (C) and (D), respectively, for an in vitro sample (4 mM TmDOTP⁵⁻, 1 mM Ca²⁺, 10% D₂O). The 3D surfaces represent the result of the fits of chemical shift δ as function of temperature T and pH (eq. [1]). The differential and independent “storage” of temperature and pH information by each of these protons is reflected by the non-overlapping 3D surfaces, a fact which can be appreciated by the variable extent of the different color tones.