Höfer M, Brand K, Deckner K, Becker J U
Biochem J. 1971 Aug;123(5):855-63. doi: 10.1042/bj1230855.
d-Glucose catabolism of a phosphofructokinase-deficient yeast Rhodotorula gracilis has been studied. By using d-glucose specifically (14)C-labelled at different positions and measuring the distribution of the label in various fractions of cell metabolism, the following results were found. 1. The pentose phosphate pathway, being the main pathway of d-glucose catabolism, simultaneously converts glucose molecules into pentose phosphates oxidatively by using two NADP-linked dehydrogenases and via the non-oxidative transketolase-transaldolase pathway. 2. From the correlation of the (14)CO(2) liberation and the d-glucose consumption and from the fact that the pentose phosphate moiety in nucleic acids is almost equally labelled from d-[1-(14)C]- and d-[6-(14)C]-glucose, it is concluded that of the glucose utilized about 80% undergoes transformation via the non-oxidative pentose phosphate pathway. Only about 20% of glucose is directly decarboxylated to pentose phosphate. 3. For further degradation it is postulated that the pentose phosphates are split into C(2) fragments and glyceraldehyde 3-phosphates. 4. All three loci of oxidative decarboxylation appear to be effective in Rh. gracilis, the oxidative part of the pentose phosphate pathway, the decarboxylation of pyruvate in the later part of the glycolytic pathway as well as the oxidation in the tricarboxylic acid cycle. 5. d-Glucose molecules taken up are only partially oxidized to CO(2): about four-fifths of each glucose molecule metabolized is incorporated into cell constituents. 6. The quantitative interrelations of the fluxes of d-glucose subunits along the catabolic pathways have been estimated and are discussed.
对缺乏磷酸果糖激酶的酵母纤细红酵母的d-葡萄糖分解代谢进行了研究。通过使用在不同位置特异性标记有(14)C的d-葡萄糖，并测量标记在细胞代谢各部分中的分布，得到了以下结果。1. 戊糖磷酸途径作为d-葡萄糖分解代谢的主要途径，通过两种与NADP相连的脱氢酶并经由非氧化转酮醇酶-转醛醇酶途径，同时将葡萄糖分子氧化转化为戊糖磷酸。2. 根据(14)CO(2)释放与d-葡萄糖消耗的相关性，以及核酸中的戊糖磷酸部分几乎被d-[1-(14)C]-葡萄糖和d-[6-(14)C]-葡萄糖等量标记这一事实，得出结论：所利用的葡萄糖中约80%通过非氧化戊糖磷酸途径进行转化。只有约20%的葡萄糖直接脱羧形成戊糖磷酸。3. 为了进一步降解，推测戊糖磷酸被分解为C(2)片段和3-磷酸甘油醛。4. 氧化脱羧的所有三个位点在纤细红酵母中似乎都是有效的，即戊糖磷酸途径的氧化部分、糖酵解途径后期丙酮酸的脱羧以及三羧酸循环中的氧化。5. 摄取的d-葡萄糖分子仅部分氧化为CO(2)：每个代谢的葡萄糖分子约五分之四被整合到细胞成分中。6. 已经估计并讨论了d-葡萄糖亚基沿分解代谢途径的通量的定量相互关系。
