Kou S C, Christensen M S, Cirillo V P
J Bacteriol. 1970 Sep;103(3):671-8. doi: 10.1128/jb.103.3.671-678.1970.
The characteristics of the inducible galactose system in Saccharomyces cerevisiae were studied by using the nonmetabolized galactose analogues, l-arabinose and d-fucose, and galactokinaseless and transportless mutants. Induced wild-type cells transport l-arabinose by facilitated diffusion. Transportless cells transport neither galactose nor l-arabinose above the noninduced rate, whereas galactokinaseless cells transport galactose l-arabinose and d-fucose by facilitated diffusion. Determination of unidirectional rate of (14)C-labeled galactose uptake by preloaded galactokinaseless cells, containing a large unlabeled free-galactose pool, showed that the rate of galactose uptake by facilitated diffusion is greater than the rate of galactose metabolism at similar external galactose concentrations.
通过使用非代谢性半乳糖类似物L-阿拉伯糖和D-岩藻糖以及半乳糖激酶缺陷型和转运缺陷型突变体，对酿酒酵母中可诱导的半乳糖系统的特性进行了研究。诱导的野生型细胞通过易化扩散转运L-阿拉伯糖。转运缺陷型细胞在非诱导速率以上既不转运半乳糖也不转运L-阿拉伯糖，而半乳糖激酶缺陷型细胞通过易化扩散转运半乳糖、L-阿拉伯糖和D-岩藻糖。对预先装载有大量未标记游离半乳糖池的半乳糖激酶缺陷型细胞摄取（14）C标记半乳糖的单向速率的测定表明，在相似的外部半乳糖浓度下，通过易化扩散摄取半乳糖的速率大于半乳糖代谢的速率。
