Demonstration of organ-nonspecific antigens in liver-specific protein.

Liver-specific protein was isolated from bovine, rabbit, and human liver. A corresponding kidney protein was isolated from rabbit kidney. The liver-specific protein and kidney-specific protein were coupled to activated CH-Sepharose 4B. Affinity chromatography was performed on columns of liver-specific protein and kidney-specific protein CH-Sepharose 4B, with sera containing antimitochondrial antibodies, smooth muscle antibodies, bile canalicular antibodies, reticular tissue antibodies, and antinuclear antibodies. The material eluted from the affinity chromatography columns was studied for immunofluorescence reaction against sections of liver, kidney, and stomach. Reactions were found of the liver-specific protein and kidney-specific protein column eluates against mitochondria, smooth muscle, double-stained bile canaliculi, reticular tissue, and nucleoli. Thus, the antigens belonging to these cell and organ constituents must have been present in the liver-specific protein (and kidney-specific protein) preparations, indicating that liver-specific protein is not a pure liver cell membrane-specific protein.