Taghikhani M, Lavi L W, Woost P G, Griffin C C
Biochim Biophys Acta. 1984 Apr 16;803(4):278-83. doi: 10.1016/0167-4889(84)90118-6.
The yeast Rhodotorula glutinis (Rhodosporidium toruloides) is capable of accumulative transport of a wide variety of monosaccharides. Initial velocity studies of the uptake of 2-deoxy-D-glucose were consistent with the presence of at least two carriers for this sugar in the Rhodotorula plasma membrane. Non-linear regression analysis of the data returned maximum velocities of 0.8 +/- 0.2 and 2.0 +/- 0.2 nmol/min per mg (wet weight) and Km values of 18 +/- 4 and 120 +/- 20 microM, respectively, for the two carriers. Kinetic studies of D-glucose transport also revealed two carriers with maximum velocities of 1.1 +/- 0.4 and 2.4 +/- 0.4 nmol/min per mg (wet weight) and Km values of 12 +/- 3 and 55 +/- 12 microM. As expected, 2-deoxy-D-glucose was a competitive inhibitor of D-glucose transport. Ki values for the inhibition were 16 +/- 8 and 110 +/- 40 microM. These Ki values were in good agreement with the Km values for 2-deoxy-D-glucose transport. D-Xylose, the 5-deoxymethyl analog of D-glucose, appears to utilize the D-glucose/2-deoxy-D-glucose carriers. This pentose was observed to be a competitive inhibitor of D-glucose (Ki values = 0.14 +/- 0.06 and 5.6 +/- 1.6 mM) and 2-deoxy-D-glucose (Ki values = 0.15 +/- 0.07 and 4.6 +/- 1.2 mM) transport.
粘红酵母（红冬孢酵母）能够对多种单糖进行累积运输。对2-脱氧-D-葡萄糖摄取的初始速度研究表明，在粘红酵母的质膜中至少存在两种该糖的载体。对数据进行非线性回归分析得出，两种载体的最大速度分别为每毫克（湿重）0.8±0.2和2.0±0.2 nmol/分钟，Km值分别为18±4和120±20 μM。对D-葡萄糖运输的动力学研究也揭示了两种载体，其最大速度分别为每毫克（湿重）1.1±0.4和2.4±0.4 nmol/分钟，Km值分别为12±3和55±12 μM。正如预期的那样，2-脱氧-D-葡萄糖是D-葡萄糖运输的竞争性抑制剂。抑制的Ki值为16±8和110±40 μM。这些Ki值与2-脱氧-D-葡萄糖运输的Km值非常吻合。D-木糖，D-葡萄糖的5-脱氧甲基类似物，似乎利用了D-葡萄糖/2-脱氧-D-葡萄糖载体。观察到这种戊糖是D-葡萄糖（Ki值 = 0.14±0.06和5.6±1.6 mM）和2-脱氧-D-葡萄糖（Ki值 = 0.15±0.07和4.6±1.2 mM）运输的竞争性抑制剂。
