Bottema C D, Rodriguez R J, Parks L W
Biochim Biophys Acta. 1985 Mar 14;813(2):313-20. doi: 10.1016/0005-2736(85)90247-0.
Fluorescence anisotropy measurements indicated that physical changes occurred in the lipids of plasma membranes of yeast sterol mutants but not in the plasma membrane of an ergosterol wild-type. Parallel experiments with model membrane liposomes verified that the physical changes in lipids observed in the sterol mutants are dependent on the sterol present and not the phospholipid composition. In addition, the physical changes in lipids observed in liposomes derived from wild-type phospholipids were eliminated by addition of ergosterol but persisted in the presence of cholesterol, cholestanol, ergostanol, or sterols from the sterol mutants. No physical changes in lipids were observed, however, in plasma membranes from a sterol auxotroph, even when the auxotroph was grown on cholesterol or cholestanol. The lack of physical changes in lipids in the sterol auxotroph may reflect the ability of the auxotroph to modify its phospholipid composition with respect to its sterol composition. These results indicate that high specificity 'sparking' sterol is not required for the regulation of overall bulk lipid properties of the plasma membrane.
荧光各向异性测量表明，酵母甾醇突变体的质膜脂质发生了物理变化，而麦角固醇野生型的质膜脂质未发生变化。对模型膜脂质体进行的平行实验证实，在甾醇突变体中观察到的脂质物理变化取决于所存在的甾醇，而非磷脂组成。此外，通过添加麦角固醇可消除源自野生型磷脂的脂质体中观察到的脂质物理变化，但在存在胆固醇、胆甾烷醇、麦角甾烷醇或甾醇突变体的甾醇时，这种变化依然存在。然而，即使甾醇营养缺陷型在胆固醇或胆甾烷醇上生长，其质膜脂质也未观察到物理变化。甾醇营养缺陷型脂质缺乏物理变化可能反映出该营养缺陷型能够根据其甾醇组成改变其磷脂组成。这些结果表明，调节质膜整体脂质性质并不需要高特异性的“引发”甾醇。
