Isolation of a Ca2+ carrier from calf heart inner mitochondrial membrane.
A protein has been isolated from calf heart inner mitochondrial membrane with the aid of an electron paramagnetic resonance (EPR) assay based on the relative binding properties of Ca2+, Mn2+, and Mg2+ to the protein. The molecular weight of this protein has been estimated to be about 3000 by urea/sodium dodecyl sulfate-gel electrophoresis and amino acid analysis. The isolated protein has been shown to have high affinity and high specificity for Ca2+ (Jeng, A. Y., Ryan T. E., and Shamoo, A. E. (1978) Proc. Natl. Acad. Sci. U. S. A. 75, 2125-2129). However, the protein was found to be contaminated with a large amount of phospholipids. There are 150 mol of phospholipids associated with each mole of the protein. The protein is delipidated using Sephadex LH-20 column chromatography. The contaminating phospholipids can be reduced to 0.1 mol of phospholipids/mol of protein. There are no detectable free fatty acids, hexosamines, or sialic acids associated with the delipidated protein. This protein is named "calciphorin," meaning calcium ionophore protein.
D000818:Animals; D002135:Calcium-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002417:Cattle; D004578:Electron Spin Resonance Spectroscopy; D005227:Fatty Acids / Q000032:analysis; D007425:Intracellular Membranes / Q000378:metabolism*; D008345:Manganese / Q000378:metabolism; D008563:Membrane Lipids / Q000032:analysis; D008565:Membrane Proteins / Q000032:analysis; D008929:Mitochondria, Heart / Q000378:metabolism*; D008970:Molecular Weight
D002135:Calcium-Binding Proteins; D005227:Fatty Acids; D008563:Membrane Lipids; D008565:Membrane Proteins; C025673:calciphorin; D008345:Manganese