Heller K B, Lin E C, Wilson T H
J Bacteriol. 1980 Oct;144(1):274-8. doi: 10.1128/jb.144.1.274-278.1980.
The specificity of the glycerol facilitator (glpF) of Escherichia coli was studied with an osmotic method. This transport system allowed the entry of polyols (glycerol and erythritol), pentitols, and hexitols. The analogous sugars were not transported. However, urea, glycine, and DL-glyceraldehyde could use this pathway to enter the cell. The glpF protein allowed the rapid efflux of preequilibrated xylitol. Glycerol surprisingly did not inhibit the uptake of xylitol, and xylitol only slightly reduced the uptake of glycerol. The observation and the insensitivity of the xylitol transport to low temperature suggest that the facilitator behaves as a membrane channel.
采用渗透法研究了大肠杆菌甘油转运蛋白（glpF）的特异性。该转运系统允许多元醇（甘油和赤藓糖醇）、戊糖醇和己糖醇进入细胞。类似的糖类则不能被转运。然而，尿素、甘氨酸和DL-甘油醛可以利用该途径进入细胞。glpF蛋白能使预平衡的木糖醇快速外流。令人惊讶的是，甘油并不抑制木糖醇的摄取，而木糖醇仅略微降低甘油的摄取。木糖醇转运对低温不敏感这一观察结果表明，该转运蛋白表现为一种膜通道。
