Mazumder C, Kundu M, Basu J, Chakrabarti P
Department of Chemistry, Bose Institute, Calcutta, India.
Lipids. 1987 Sep;22(9):609-12. doi: 10.1007/BF02533937.
A nystatin-resistant mutant of Aspergillus niger has been isolated and used as a model system to study the effect of altered sterol levels on lipid composition, transport behavior and physical properties of membrane lipids. There is a decrease in the sterol to phospholipid ratio in the mutant compared to the wild type. Although there is no qualitative change in phospholipid composition, the mutant contains a higher amount of phosphatidylcholine and a lower amount of phosphatidylethanolamine compared to the wild type. The most significant change is the elevated level of linoleic acid in the mutant, concomitant with a decreased level of oleic acid. These adaptive changes to nystatin resistance are manifested in the altered thermotropic behavior of membrane lipids as studied by the steady-state fluorescence polarization technique. These changes are also associated with altered membrane permeability as evidenced by the change in Vmax values for uptake of some amino acids in the mutant compared to the wild type.
已分离出黑曲霉的制霉菌素抗性突变体，并将其用作模型系统，以研究甾醇水平改变对膜脂的脂质组成、转运行为和物理性质的影响。与野生型相比，突变体中甾醇与磷脂的比例降低。虽然磷脂组成没有质的变化，但与野生型相比，突变体含有更高含量的磷脂酰胆碱和更低含量的磷脂酰乙醇胺。最显著的变化是突变体中亚油酸水平升高，同时油酸水平降低。通过稳态荧光偏振技术研究发现，这些对制霉菌素抗性的适应性变化表现在膜脂热致行为的改变上。这些变化还与膜通透性的改变有关，与野生型相比，突变体中某些氨基酸摄取的Vmax值变化证明了这一点。
