Vitamin D-Dependent Calcium Binding Protein of Rat Renal Cortex
A vitamin D-dependent calcium binding protein (CaBP) has been partially purified from rat renal cortex. Its molecular weight is about 28.000 daltons, more than twice that of the vitamin D-dependent rat intestinal CaBP. The apparent pK of the partially purified renal CaBP is 5.0 and its binding capacity 22 nanomoles Ca bound/mg protein. No renal CaBP was found in kidneys from rachitic rats or in the medulla of normal animals. In contrast with intestinal CaBP, renal CaBP activity does not appear to vary markedly with calcium intake, plasma calcium concentration or urinary calcium excretion.
KeywordsPhosphorus Depression Trypsin Dextran Spectrophotometry
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- FREUND, T.S., BRONNER, F.: Regulation of intestinal calcium binding protein by calcium intake in the rat. Am.J.Physiol. (in press).Google Scholar
- FREUND, T.S., BURNS, M., BRONNER, F.: Calcium binding protein (CaBP), vitamin D and Ca intake in rats. In: Calcified Tissue: Proc. 9th European Symposium on Calcified Tissues. (H. Czitober and J. Eschberger, Eds.) Vienna: Facta Publication 1973a, 263–269.Google Scholar
- FREUND, T.S., HERMSDORF, C., CUISINIER-GLEIZES, P., BRONNER, F.: Calcium binding proteins (CaBP) of rat intestine and kidney. Fed. Proc. 32, 424Abs (1973b).Google Scholar
- HERMSDORF, C.L., BRONNER, F.: Vitamin D-dependent calcium binding protein from rat kidney. Biochim. Biophys. Acta (in press).Google Scholar
- HURWICH, B.J., GELMONT, D., MENCZEL, J., LENDER, M., MOR, E.: Calcium binding protein (CaBP) in normal and uremic human and rat kidneys. In: Calcified Tissue: Proc. 9th European Symposium on Calcified Tissues. (H. Czitober and J. Eschberger, Eds.) Vienna: Facta Publication 1973, 105–108.Google Scholar
- WALSER, M.: Renal excretion of alkaline earths. In: Mineral Metabolism–An Advanced Treatise (C.L. Comar and F. Bronner, Eds.). Vol. III, pp. 260–261. Calcium Physiology. New York and London: Academic Press 1969.Google Scholar