Ahmed S, Booth I R
Biochem J. 1981 Dec 15;200(3):583-9. doi: 10.1042/bj2000583.
The relationship between the steady state lactose accumulation (delta plac) and the magnitude of the membrane potential (delta psi) and pH gradient (delta pH) has been studied at pHo5.5 and pHo7.5. An attempt has been made to differentiate between two possible means by which lactose accumulation may be reduced below the proton-motive force (delta p). Firstly, that delta psi and delta pH are not equivalent in driving lactose transport and secondly, that 'slip' reactions (beta-galactoside exit via the carrier without a proton) may reduce accumulation. The data support the latter; however, our conclusions are tempered by the observation that the apparent stoichiometry (delta plac/delta p) increases to a value of at least 2 at values of delta p below 130 mV.
在细胞外pH值为5.5和7.5的条件下，研究了稳态乳糖积累（δplac）与膜电位（δψ）大小和pH梯度（δpH）之间的关系。已尝试区分两种可能导致乳糖积累低于质子动力（δp）的方式。首先，δψ和δpH在驱动乳糖转运方面并不等效；其次，“滑移”反应（β-半乳糖苷通过载体在无质子的情况下流出）可能会减少积累。数据支持后者；然而，我们的结论受到以下观察结果的影响：在δp低于130 mV时，表观化学计量比（δplac/δp）增加到至少2的值。
