Hamasaki N, Hardjono I S, Minakami S
Biochem J. 1978 Jan 15;170(1):39-46. doi: 10.1042/bj1700039.
Phosphoenolpyruvate was transported through the erythrocyte membrane at low pH (4.5-6.5). The influx was observed not only in an iso-osmotic sucrose medium, but also in 0.1 M-citrate solution, but it was negligible in an iso-osmotic NaC1 solution. Efflux, however, was observed in both the sucrose and NaC1 solutions. Compounds derived from phosphoenolpyruvate by replacing the methene group by similarly hydrophobic groups such as hydrogen or the methyl group were permeant but those with the hydrophilic hydroxymethyl group were impermeant. This transport was inhibited by the treatment with 4-acetamido-4'-isothiocyanostilbene-2,2'-disulphonic acid or pyridoxal phosphate/NaBH4, which are known to be specific for the transport of anions such as C1-, SO42- and HPO42-. It showed saturation kinetics with respect to phosphoenolpyruvate concentration in the medium. These results suggest that the transport of phosphoenolpyruvate is mediated by the anion-transport system. Although phosphoenolpyruvate was transported against the concentration gradient, the transport was characterized as a passive transport, and this apparent uphill transport was interpreted by the Donnan equilibrium.
在低pH值（4.5 - 6.5）条件下，磷酸烯醇丙酮酸可通过红细胞膜进行转运。不仅在等渗蔗糖培养基中观察到了内流，在0.1 M柠檬酸盐溶液中也观察到了内流，但在等渗氯化钠溶液中内流可忽略不计。然而，在蔗糖溶液和氯化钠溶液中均观察到了外流。通过用类似疏水基团（如氢或甲基）取代亚甲基而从磷酸烯醇丙酮酸衍生得到的化合物是可通透的，但含有亲水性羟甲基的化合物则不可通透。用4 - 乙酰氨基 - 4'-异硫氰基芪 - 2,2'-二磺酸或磷酸吡哆醛/硼氢化钠处理可抑制这种转运，已知这两种物质对诸如Cl-、SO42-和HPO42-等阴离子的转运具有特异性。它相对于培养基中磷酸烯醇丙酮酸的浓度呈现出饱和动力学。这些结果表明，磷酸烯醇丙酮酸的转运是由阴离子转运系统介导的。尽管磷酸烯醇丙酮酸是逆浓度梯度进行转运的，但这种转运被表征为被动转运，并且这种明显的上坡转运是由唐南平衡来解释的。
