Interaction of the Carbohydrate-Binding Protein Concanavalin a With Normal and Transformed Cells

Abstract

\-that such sites can be found on the surface membrane of normal cells after treatment with trypsin, and that the change in the surface structure from normal to transformed occurs in cells that are abortively transformed.Agglutination of cells by substances with different binding sites should be of value in elucidating the structural changes in the surface membrane that accompany the transformation of normal cells by carcinogenic agents. A substance from wheat germ that agglutinates transformed cells has previously been described.1' 2 Studies with this substance have indicated that this agglutinin is a glycoprotein,2 that the agglutination can be inhibited by competition with Nacetylglucosamine,2 3 and that after treatment with proteases, untransformed cells can be agglutinated and contain the same or similar receptor sites as transformed cells.4The present experiments were undertaken to find proteins with different binding sites that can be used for studies on the surface membrane of normal and transformed cells. It was found that when cells were dissociated with disodium versenate and not treated with trypsin, the crystalline Jack bean protein concanavalin A5 (ConA), which binds a-methyl-D-glucopyranoside6 7 and various other carbohydrates, agglutinated cells transformed by viral and nonviral carcinogens, but did not agglutinate normal cells and the untransformed cell line 3T3. The present communication reports the results of these experiments with 1418

Agglutination of Blastospores of Candida albicans by Concanavalin A and its Relationship with the Distribution of Mannan Polymers and the Ultrastructure of the Cell Wall

“…These criteria for estimating the Con A-agglutination are essentially those adopted for mammalian cell agglutination (Inbar & Sachs, 1969).…”

Inhibition of normal and transformed fibroblast aggregation by skeletal muscle F‐actin

“…Transformation leads to changes in agglutination by plant lectins [6] and in contact inhibition of growth [7] and was shown to involve a decrease in membrane-associated actin in the case of fibroblasts [1,2]. It was therefore interesting to examine whether exogenous actin or myosin could influence surface-dependent properties of cells such as aggregation.…”

Molecules at the External Nuclear Surface

“…utilizing plant lectins as molecular probes for their identification (Kornfeld et al ., 1971 ;Inbar and Sachs, 1969 ;Burger and Goldberg, 1967 ;Cline and Livingston, 1971) Furthermore, much earlier work utilizing whole cell particle electrophoresis as the tool for examining the nature of biological surfaces tended to be concerned with oligosaccharides and terminal monosaccharides of mammalian plasma membranes, in particular the plasma membrane of the erythrocyte (Ambrose, 1965 ;Heard and Seaman, 1960 ;Seaman and Heard, 1960) . In short, comparatively little work has been concerned with the nature of the exposed surfaces of cellular organelles such as mitochondria, lysosomes, and nuclei, and essentially no work has been performed on terminal residues of macromolecules of the less convoluted membranes of the smooth and rough endoplasmic reticulum and the Golgi apparatus .…”