Sterols regulate several physico-chemical properties of biological membranes that are considered to be linked to function. Ergosterol is the main sterol molecule found in the cell membranes of yeasts and other fungi. Like the cholesterol found in mammalian cells, ergosterol has been proposed to have an ordering and condensing effect on saturated phospholipid membranes. The effects of cholesterol have been investigated extensively and result in an increase in the membrane thickness and the lipid acyl chain order. Less information is available on the effects of ergosterol on phospholipid membranes. Neutron Diffraction (ND) was used to characterize the effect of ergosterol on lipid multilayers prepared with deuterated natural phospholipids extracted from the yeast Pichia pastoris. The data show that the effect of ergosterol on membranes prepared from the natural phospholipid extract rich in unsaturated acyl chains, differs from what has been observed previously in membranes rich in saturated phospholipids. In contrast to cholesterol in synthetic phospholipid membranes, the presence of ergosterol up to 30 mol % in yeast phospholipid membranes only slightly altered the multilayer structure. In particular, only a small decrease in the multilayer d-spacing was observed as function of increasing ergosterol concentrations. This result highlights the need for further investigation to elucidate the effects of ergosterol in biological lipid mixtures.

中文翻译：

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麦角固醇对氘化酵母磷脂多层的层间间距的影响。

甾醇调节生物膜的几种物理化学特性，这些特性被认为与功能有关。麦角固醇是在酵母和其他真菌的细胞膜中发现的主要固醇分子。像哺乳动物细胞中发现的胆固醇一样，麦角固醇被提议对饱和磷脂膜具有有序和凝聚作用。胆固醇的作用已被广泛研究，并导致膜厚度和脂质酰基链顺序增加。关于麦角固醇对磷脂膜的作用的信息很少。中子衍射（ND）用于表征麦角固醇对用从酵母毕赤酵母提取的氘化天然磷脂制备的脂质多层的作用。数据表明，麦角固醇对由富含不饱和酰基链的天然磷脂提取物制备的膜的作用不同于先前在富含饱和磷脂的膜中观察到的作用。与合成磷脂膜中的胆固醇相反，酵母磷脂膜中高达30 mol％的麦角固醇的存在仅轻微改变了多层结构。尤其是，观察到多层d-间距的小幅下降是麦角固醇浓度增加的函数。该结果强调需要进一步研究以阐明麦角固醇在生物脂质混合物中的作用。与合成磷脂膜中的胆固醇相反，酵母磷脂膜中高达30 mol％的麦角固醇的存在仅轻微改变了多层结构。尤其是，观察到多层d-间距的小幅下降是麦角固醇浓度增加的函数。该结果强调需要进一步研究以阐明麦角固醇在生物脂质混合物中的作用。与合成磷脂膜中的胆固醇相反，酵母磷脂膜中高达30 mol％的麦角固醇的存在仅轻微改变了多层结构。尤其是，观察到多层d-间距的小幅下降是麦角固醇浓度增加的函数。该结果强调需要进一步研究以阐明麦角固醇在生物脂质混合物中的作用。