Figure 5.

Q8 increases the anisotropy of DPH fluorescence in liposomes. Liposomes comprised of a polar lipid extract from E. coli, with or without supplementary Q8, were prepared in 0.1 m potassium phosphate, pH 7.4, 0.1 mm K⁺-EDTA and labeled with DPH (0.2 mol % relative to phospholipid) before the anisotropy of DPH fluorescence was measured as described under “Experimental procedures.” Q8 was omitted (closed circles) or added to attain 1% (open circles) Q8 relative to lipid (w/w). Measurements were made at 5 °C intervals over a 20–45 °C temperature range. Duplicate measurements from each of two experiments are shown.