Lavi L E, Hermiller J B, Griffin C C
Biochim Biophys Acta. 1981 Oct 20;648(1):1-5. doi: 10.1016/0005-2736(81)90118-8.
The kinetics of D-ribose transport by Rhodotorula glutinis were investigated over a 1 000-fold range of sugar concentrations. Analysis of the saturation isotherm revealed the presence of two carrier systems for D-ribose in the Rhodotorula plasma membrane. These two carriers exhibited Km values of 1.3 and 30 mM. At saturating concentrations of D-ribose, the low Km carrier contributes less than 10% to the total rate of transport. Although D-ribose is metabolized rapidly by Rhodotorula, intracellular free sugar concentrations exceed those in the medium. In addition, the transport of this pentose is inhibited by the proton-conductors, 2,4-dinitrophenol and carbonylcyanide m-chlorophenylhydrazone. These data suggest that Rhodotorula cells are capable of an energy-dependent, concentrative transport of D-ribose.
在1000倍的糖浓度范围内研究了粘红酵母对D-核糖的转运动力学。饱和等温线分析表明，在粘红酵母的质膜中存在两种D-核糖载体系统。这两种载体的Km值分别为1.3 mM和30 mM。在D-核糖饱和浓度下，低Km载体对总转运速率的贡献小于10%。尽管粘红酵母能迅速代谢D-核糖，但细胞内游离糖浓度超过培养基中的浓度。此外，质子导体2,4-二硝基苯酚和羰基氰化物间氯苯腙可抑制这种戊糖的转运。这些数据表明，粘红酵母细胞能够进行能量依赖的、浓缩性的D-核糖转运。
