Electrophoretic analysis of microsomal smooth membrane proteins in rat liver and in Morris hepatoma 5123C.

Smooth microsomal cell membranes were isolated by density gradient centrifugation from normal rat liver and from the well-differentiated Morris hepatoma 5123C. The proteins were then extracted from the smooth membrane fraction and compared on acrylamide gel by the split-gel technique and by coelectrophoresis of dually labeled proteins. This analysis revealed the lack of two liver membrane components in the membrane of the hepatoma. The change of protein composition of the cell membrane of a welldifferentiated liver tumor is discussed briefly.