Delorme A C, Danan J L, Mathieu H
J Biol Chem. 1983 Feb 10;258(3):1878-84.
Mouse kidney, a vitamin D target organ, was investigated for the presence of vitamin D-dependent calcium-binding proteins (CaBP). Mouse kidney cytosol was fractionated by several biochemical methods including gel filtration chromatography, gel permeation high performance liquid chromatography, and chromatofocusing. Mouse kidney was found to possess two CaBPs which completely differed biochemically and exhibited no cross-immunoreactivity. One had a molecular weight of 25,000 and a pI of 5.9. The other, with a molecular weight of 10,000 and a pI of 4.9, was biochemically identical with mouse duodenal 10,000 CaBP. In addition, mouse renal and duodenal 10,000 CaBPs were immunologically identical. Moreover, the 10,000 CaBP was the predominant CaBP in mouse kidney since the latter contained about twice as much 10,000 CaBP as 25,000 CaBP (in mol/mg of renal cytosolic protein). In vitro incorporation of [3H]leucine into renal 10,000 CaBP demonstrated that it is synthesized in situ by mouse kidney. Renal 10,000 CaBP was already present during fetal life, and reached its adult level during the first week after birth. The vitamin D dependency of both mouse renal 10,000 and 25,000 CaBPs was assessed by their decrease in vitamin D-deficient mice and subsequent rise after 1,25-dihydroxyvitamin D3 injection. The concomitant presence of substantial amounts of two vitamin D-dependent CaBPs in mouse kidney is peculiar to this organ, which might consequently provide a unique model for studying the hormonal expressions of 1,25-dihydroxyvitamin D3.
作为维生素D的靶器官，对小鼠肾脏中维生素D依赖性钙结合蛋白（CaBP）的存在情况进行了研究。通过多种生化方法对小鼠肾脏胞质溶胶进行了分级分离，这些方法包括凝胶过滤色谱法、凝胶渗透高效液相色谱法和色谱聚焦法。发现小鼠肾脏拥有两种CaBP，它们在生化性质上完全不同，且不存在交叉免疫反应。一种CaBP的分子量为25,000，等电点为5.9。另一种CaBP的分子量为10,000，等电点为4.9，在生化性质上与小鼠十二指肠10,000 CaBP相同。此外，小鼠肾脏和十二指肠的10,000 CaBP在免疫上是相同的。而且，10,000 CaBP是小鼠肾脏中的主要CaBP，因为后者所含的10,000 CaBP量约为25,000 CaBP的两倍（以每毫克肾脏胞质蛋白中的摩尔数计）。[3H]亮氨酸在体外掺入肾脏10,000 CaBP表明它是由小鼠肾脏原位合成的。肾脏10,000 CaBP在胎儿期就已存在，并在出生后的第一周达到成年水平。通过维生素D缺乏小鼠中两种CaBP含量的降低以及随后注射1,25 - 二羟基维生素D3后的升高，评估了小鼠肾脏中10,000和25,000 CaBP对维生素D的依赖性。小鼠肾脏中同时存在大量两种维生素D依赖性CaBP是该器官所特有的，因此它可能为研究1,25 - 二羟基维生素D3的激素表达提供一个独特的模型。
