Ultrastructural detection of concanavalin surface receptors in normal and in polyoma-transformed cells.

Abstract

AbstractThe ultrastructural distribution of concanavalin A receptor sites on the surface of normal hamster embryo cells and polyoma‐transformed cells was studied by means of the concanavalin‐peroxidase method. In vertical sections of normal cells, the precipitate appeared as a uniform surface layer, which gave the appearance of a homogeneous coat when seen in surface views. The reacting layer on the surface of transformed cells was similar, except in approximately one‐third of the polyoma‐transformed cells. The latter showed a more discontinuous surface layer line in vertical sections, while in tangential sections, the coat was found to be formed by isolated clusters of reacting precipitate. These results indicate that the surface of both normal and transformed cells equally possess exposed binding sites to concanavalin A. The receptors tend to be more irregularly distributed on the surface of some transformed cells.