Loginova N B, Trotsenko Iu A
Mikrobiologiia. 1979 Mar-Apr;48(2):202-7.
The activity of pyruvate and phosphoenolpyruvate carboxylases was determined in cell extracts of obligate and facultative methylotrophs which metabolized monocarbon reduced compounds via different pathways. Phosphoenolpyruvate carboxylase was found to be the only enzyme responsible for the high level of CO2 fixation by methylotrophs with the serine pathway (Methylosinus trichosporium, Hyphomicrobium vulgare, Pseudomonas methylica). Methylotrophs with the hexulose phosphate pathway Mehylobacter chroococcum, Methylomonas methanica, Pseudomonas oleovorans, Arthrobacter globiformis) and yeast (Candida methylica) assimilated less CO2 but contained more enzymes involved in arboxylation of phosphoenolpyruvate (phosphoenolpyruvate carboxylase, EG 4.1.1.31; phosphoenolpyruvate carboxykinase, EC 4.1.1.32) or pyruvate (pyruvate carboxylase, EC 6.4.1.1; malic-enzyme, EC 4.1.1.40). Phosphoenolpyruvate carboxytransphosphorylase (EC 4.1.1.38) was not found in any of the studied strains. The properties and the role of carboxylases in the metabolism of methylotrophs are discussed.
在通过不同途径代谢单碳还原化合物的专性和兼性甲基营养菌的细胞提取物中，测定了丙酮酸羧化酶和磷酸烯醇丙酮酸羧化酶的活性。发现磷酸烯醇丙酮酸羧化酶是通过丝氨酸途径进行甲基营养的菌（嗜甲基丝孢菌、普通生丝微菌、甲基假单胞菌）中负责高水平二氧化碳固定的唯一酶。具有磷酸己糖途径的甲基营养菌（嗜球甲基杆菌、甲烷甲基单胞菌、食油假单胞菌、球形节杆菌）和酵母（甲基假丝酵母）同化的二氧化碳较少，但含有更多参与磷酸烯醇丙酮酸羧化（磷酸烯醇丙酮酸羧化酶，EC 4.1.1.31；磷酸烯醇丙酮酸羧激酶，EC 4.1.1.32）或丙酮酸羧化（丙酮酸羧化酶，EC 6.4.1.1；苹果酸酶，EC 4.1.1.40）的酶。在所研究的任何菌株中均未发现磷酸烯醇丙酮酸羧基转磷酸化酶（EC 4.1.1.38）。本文讨论了羧化酶在甲基营养菌代谢中的性质和作用。
