Figure 7. Analysis of membrane order by fluorescence spectroscopy study.

Fungal cells were grown at pH 7.2, 37 °C in the presence of 5% CO₂. Two probes, TMA-DPH and t-PnA, were selected for fluorescence anisotropy studies. (A) Fluorescence anisotropy from probe TMA-DPH reveals a small but significant difference in anisotropy values of the three membranes. (B) Mean fluorescence lifetime studies with t-PnA indicate a less ordered membrane in mutants when compared to WT. (C) The long lifetime component of t-PnA fluorescence decay is the highest in WT and typical of a gel phase, thus demonstrating that WT membranes are more ordered than the two mutants. The long lifetime component values in Δsmt1 are typical of a l_o phase. Results are means ± SD of three independent experiments. ¥P<0.05, Δgcs1 versus WT; ^πP<0.05, Δsmt1 versus WT.