(A) Assessment of the molecular mass of UCP1 in 10MNG/cardiolipin by size exclusion chromatography [36]. Inset shows the mass composition of the major peak. (B) The apparent molecular mass of native UCP1 and ADP/ATP carrier in blue native gels [97]. Mitochondrial membrane extracts from lamb brown adipose tissue (UCP1, left), rat liver (ADP/ATP carrier, middle) and yeast mitochondria (monomer and covalently linked dimer of the ADP/ATP carrier AAC3, right) were prepared in 1% dodecylmaltoside and separated in 6–18% (w/v) polyacrylamide gels. (C) Isothermal titration calorimetry of purified UCP1 with GDP [36]. The enthalpy changes associated with the titration of GDP into UCP1 at 4 °C (top), and corresponding isotherms fitted to a one-site binding model with ∆H, Kd, and stoichiometry as fitting parameters (bottom).