Dyer J, Barker P J, Shirazi-Beechey S P
Institute of Biological Sciences, University of Wales, Aberystwyth, Ceredigion, United Kingdom.
Biochem Biophys Res Commun. 1997 Jan 23;230(3):624-9. doi: 10.1006/bbrc.1996.6018.
It is known that dietary carbohydrates regulate the activity of the intestinal SGLT1. We have demonstrated that modifications in SGLT1 activity are due to alterations in SGLT1 expression in response to the sugar content of the diet. To assess the correlation between changes in the activity of SGLT1 and the abundance of SGLT1 protein, we have employed a method for the quantitative measurement of immunoreactive proteins. A calibration curve has been constructed using either a nonadecapeptide (amino acids 402-420), or a recombinant protein corresponding to amino acids 554-640 of the SGLT1 sequence. Immunoblotting the protein samples concurrently with specific quantities of either the peptide or recombinant standard, using antibodies raised against these antigens, enabled accurate quantification of the absolute amounts of immunoreactive protein in the samples. The amount of SGLT1 protein correlates well with measurements of SGLT1 activity. The modulation of the activity of SGLT1 in response to lumenal sugars is due to corresponding changes in the absolute levels of SGLT1 protein.
已知膳食碳水化合物可调节肠道SGLT1的活性。我们已经证明，SGLT1活性的改变是由于饮食中糖含量导致SGLT1表达发生变化所致。为了评估SGLT1活性变化与SGLT1蛋白丰度之间的相关性，我们采用了一种定量测量免疫反应性蛋白的方法。使用一种十九肽（氨基酸402 - 420）或与SGLT1序列中氨基酸554 - 640对应的重组蛋白构建了校准曲线。使用针对这些抗原产生的抗体，将蛋白质样品与特定量的肽或重组标准品同时进行免疫印迹，能够准确量化样品中免疫反应性蛋白的绝对量。SGLT1蛋白的量与SGLT1活性的测量结果密切相关。SGLT1活性对肠腔糖的调节是由于SGLT1蛋白绝对水平的相应变化。
