Zundel M, Nambiar K P, Boswell G, Bloch K
James Bryant Conant Laboratories, Department of Chemistry, Harvard University, Cambridge 02138.
Biochemistry. 1989 Jun 13;28(12):5161-4. doi: 10.1021/bi00438a037.
6-Fluorocholesterol supports the growth of the sterol-requiring yeast mutant GL7 albeit less efficiently than cholesterol or ergosterol. When the fluoro analogue is combined with very much smaller amounts of cholesterol, the growth response to the sterol pair is synergistic, i.e., greater than additive. On further addition of trace amounts of ergosterol to the 6-fluorocholesterol-cholesterol pair, an additional synergistic growth response is observed. On 6-fluorocholesterol alone, the growth rate of the yeast mutant is slow initially, but after several transfers of such cells to the same media containing the fluoro analogue, growth improves substantially. When incorporated into artificial membranes, cholesterol and its 6-fluoro analogue have essentially identical effects on membrane fluidity as judged from microviscosity measurements. The contrasting responses of artificial membranes and whole cells to the 6-fluoro analogue of cholesterol might be due to sterol-protein interactions in natural membranes.
6-氟胆固醇能支持需要固醇的酵母突变体GL7的生长，尽管其效率低于胆固醇或麦角固醇。当这种氟代类似物与非常少量的胆固醇结合时，对这两种固醇的生长反应是协同的，即大于相加效应。在6-氟胆固醇-胆固醇组合中进一步添加微量麦角固醇时，会观察到额外的协同生长反应。单独使用6-氟胆固醇时，酵母突变体的生长速率最初较慢，但将这些细胞多次转移到含有该氟代类似物的相同培养基中后，生长显著改善。根据微粘度测量判断，当胆固醇及其6-氟类似物掺入人工膜中时，它们对膜流动性的影响基本相同。人工膜和完整细胞对胆固醇6-氟类似物的不同反应可能是由于天然膜中的固醇-蛋白质相互作用。
