低浓度下成纤维细胞中2-脱氧葡萄糖摄取动力学异常。

'Abnormality of 2-deoxyglucose uptake kinetics in fibroblasts at low concentrations.

作者信息

Cynober L, Auget J L, Agneray J, Ekindjian O G

出版信息

Biochem Biophys Res Commun. 1984 Sep 17;123(2):535-42. doi: 10.1016/0006-291x(84)90262-6.

Abstract

2-deoxyglucose uptake rates at low sugar concentrations (less than 500 microM) appeared to be lower than those predicted by the Michaelis-Menten model which correctly described higher concentrations. This phenomenon which we will call concentration-dependent transport lag, was also observed for L-glucose uptake which suggest that this phenomenon is carrier-independent. A model involving the perimembrane space is developed which, for L-glucose, gives k1 = 0.931 +/- 0.072 X 10(-6) l X mg protein-1 X minute-1, k2 = 2.97 +/- 0.19 X 10(-7) l X mg protein-1 X minute-1 and So = 88,8 +/- 4,3 microM; where k1 is the diffusion constant in the cell membrane, k2 is the diffusion constant in the perimembrane space and So the sugar concentration required in the external medium in order to provide an équivalent sugar concentration in the transport carrier area.

摘要

在低糖浓度（低于500微摩尔）下，2-脱氧葡萄糖的摄取速率似乎低于米氏模型预测的值，而该模型能正确描述较高浓度时的情况。我们将这种现象称为浓度依赖性转运滞后，在L-葡萄糖摄取过程中也观察到了这一现象，这表明该现象与载体无关。我们建立了一个涉及膜周间隙的模型，对于L-葡萄糖，该模型得出k1 = 0.931±0.072×10⁻⁶升×毫克蛋白⁻¹×分钟⁻¹，k2 = 2.97±0.19×10⁻⁷升×毫克蛋白⁻¹×分钟⁻¹，So = 88.8±4.3微摩尔；其中k1是细胞膜中的扩散常数，k2是膜周间隙中的扩散常数，So是外部介质中为在转运载体区域提供等效糖浓度所需的糖浓度。