Teusink B, Passarge J, Reijenga C A, Esgalhado E, van der Weijden C C, Schepper M, Walsh M C, Bakker B M, van Dam K, Westerhoff H V, Snoep J L
E.C. Slater Institute, BioCentrum Amsterdam, University of Amsterdam, the Netherlands.
Eur J Biochem. 2000 Sep;267(17):5313-29. doi: 10.1046/j.1432-1327.2000.01527.x.
This paper examines whether the in vivo behavior of yeast glycolysis can be understood in terms of the in vitro kinetic properties of the constituent enzymes. In nongrowing, anaerobic, compressed Saccharomyces cerevisiae the values of the kinetic parameters of most glycolytic enzymes were determined. For the other enzymes appropriate literature values were collected. By inserting these values into a kinetic model for glycolysis, fluxes and metabolites were calculated. Under the same conditions fluxes and metabolite levels were measured. In our first model, branch reactions were ignored. This model failed to reach the stable steady state that was observed in the experimental flux measurements. Introduction of branches towards trehalose, glycogen, glycerol and succinate did allow such a steady state. The predictions of this branched model were compared with the empirical behavior. Half of the enzymes matched their predicted flux in vivo within a factor of 2. For the other enzymes it was calculated what deviation between in vivo and in vitro kinetic characteristics could explain the discrepancy between in vitro rate and in vivo flux.
本文研究酵母糖酵解的体内行为是否可以根据组成酶的体外动力学特性来理解。在非生长、厌氧、压缩的酿酒酵母中，测定了大多数糖酵解酶的动力学参数值。对于其他酶，收集了适当的文献值。通过将这些值插入糖酵解的动力学模型中，计算通量和代谢物。在相同条件下测量通量和代谢物水平。在我们的第一个模型中，分支反应被忽略。该模型未能达到实验通量测量中观察到的稳定稳态。引入通往海藻糖、糖原、甘油和琥珀酸的分支确实允许这样的稳态。将这个分支模型的预测与经验行为进行了比较。一半的酶在体内的预测通量与实际通量相差不超过2倍。对于其他酶，计算了体内和体外动力学特征之间的偏差，以解释体外速率和体内通量之间的差异。
