Waites M J, Quayle J R
J Gen Microbiol. 1981 Jun;124(2):309-16. doi: 10.1099/00221287-124-2-309.
Crude extracts of Candida boidinii grown on glucose, xylose or ethanol gave single peaks of classical transketolase activity following chromatography, on columns of hydroxylapatite; the enzyme was heat-stable and showed no appreciable activity with formaldehyde as acceptor in place of ribose 5-phosphate. Extracts of methanol-grown cells showed two peaks of transketolase activity following chromatography on both hydroxylapatite and DEAE-cellulose. One peak was identified with that found for the cells grown on substrates other than methanol; the other peak showed dihydroxyacetone synthase activity in addition to transketolase activity. Both activities in the latter peak were very unstable and have been ascribed to one enzyme on the basis of identical rates of denaturation at all temperatures tested between 0 and 40 degrees C. It is suggested that this enzyme is a special transketolase synthesized only during methylotrophic growth of the yeast and in contrast to classical transketolase, is capable of using equally well either formaldehyde or ribose 5-phosphate as glycolaldehyde acceptor. A method based on heat treatment has been suggested for the simultaneous assay of both transketolases present in crude extracts of a methylotrophically grown yeast.
在葡萄糖、木糖或乙醇上生长的博伊丁假丝酵母的粗提取物，经羟基磷灰石柱层析后，呈现出经典转酮醇酶活性的单峰；该酶对热稳定，并且当以甲醛替代5-磷酸核糖作为受体时，未显示出明显活性。甲醇培养细胞的提取物在羟基磷灰石和DEAE-纤维素上进行层析后，显示出两个转酮醇酶活性峰。其中一个峰与在除甲醇以外的底物上生长的细胞中发现的峰一致；另一个峰除了具有转酮醇酶活性外，还显示出二羟基丙酮合酶活性。后一个峰中的两种活性都非常不稳定，并且根据在0至40摄氏度之间所有测试温度下相同的变性速率，将它们归因于一种酶。有人提出，这种酶是一种特殊的转酮醇酶，仅在酵母的甲基营养生长过程中合成，并且与经典转酮醇酶不同，它能够同样良好地使用甲醛或5-磷酸核糖作为乙醇醛受体。有人提出了一种基于热处理的方法，用于同时测定甲基营养生长酵母粗提取物中存在的两种转酮醇酶。
