Figure 1.

DSC curves of alkaliphilic Bacillus pseudofirmus OF4 F₁F₀ and cytochrome caa₃ embedded in phospholipids singly or in combination. The molar ratio of F₁F₀ and caa₃ is one and the weight ratio of phospholipids to protein is 1.5 in all cases. These vesicles are prepared by the cholate dialysis method. Curve A shows the exothermic thermodenaturation of 0.5 mg F₁F₀ embedded in phospholipid vesicles. Curve B is the DSC thermogram of 0.105 mg/ml caa₃ embedded in phospholipid vesicles. Curve C is the DSC profile of phospholipid vesicles embedded with a mixture of 0.5 mg F₁F₀ and 0.105 mg caa₃. Curve D is a mixture of phospholipid vesicles, embedded individually with either 0.5 mg F₁F₀ or 0.105 mg caa₃. A total of twenty-one assays were conducted on two independent preparations. The standard deviations for the transition temperatures were in the range of 0.1–0.3 degrees and for enthalpy changes were 0.5–0.8 Kcal/mmol.