甾醇在活生物体中执行必要的结构和信号功能。麦角甾醇有助于流动性,渗透性,酵母膜中蛋白质的微域形成和功能。在我们的研究中,地莫甾醇是最成功的补偿麦角甾醇在酿酒酵母中的缺乏,除了豆甾醇和谷甾醇.这三种甾醇支持细胞生长而不引起严重的形态学缺陷,不像胆固醇,7-脱氢胆固醇,月桂甾醇,胆甾醇或羊毛甾醇。连同麦角固醇,它们还能够使hem1Δ细胞的质膜电位更接近野生型水平。此外,去甲甾醇比麦角甾醇赋予酵母更高的耐热性。一些甾醇抵消了多烯的抗真菌毒性,唑类和特比萘芬对hem1Δ细胞。植物甾醇(豆甾醇,谷甾醇)和desmosterol确保了类似于麦角甾醇的hem1Δ细胞中葡萄糖诱导的H-ATPase活化,而胆固醇和7-脱氢胆固醇效果较差.外源性麦角甾醇,豆甾醇,谷甾醇,在抑制浓度的氟康唑存在下,去甲甾醇和胆固醇也改善了光滑梭菌和白色念珠菌的生长。将外源甾醇适当掺入膜中,对膜功能的副作用最小,主要受甾醇酰基链结构的影响,更少受到它们的环结构的影响。
Sterols perform essential structural and signalling functions in living organisms.
Ergosterol contributes to the fluidity, permeability, microdomain formation and functionality of proteins in the yeast membrane. In our study, desmosterol was the most successful at compensating for the lack of
ergosterol in Saccharomyces cerevisiae, besides stigmasterol and sitosterol. These three sterols supported cell growth without causing severe morphological defects, unlike cholesterol, 7-dehydrocholesterol, lathosterol, cholestanol or lanosterol. Together with
ergosterol, they were also able to bring the plasma membrane potential of hem1Δ cells closer to the level of the wild type. In addition, desmosterol conferred even higher thermotolerance to yeast than
ergosterol. Some sterols counteracted the antifungal toxicity of polyenes, azoles and terbinafine to hem1Δ cells. Plant sterols (stigmasterol, sitosterol) and desmosterol ensured the glucose-induced activation of H+-ATPase in hem1Δ cells analogously to ergosterol, whereas cholesterol and 7-dehydrocholesterol were less effective. Exogenous
ergosterol, stigmasterol, sitosterol, desmosterol and cholesterol also improved the growth of Candida glabrata and Candida albicans in the presence of inhibitory concentration of fluconazole. The proper incorporation of exogenous sterols into the membrane with minimal adverse side effects on membrane functions was mainly influenced by the structure of the sterol acyl chain, and less by their ring structures.