Further Evidence for Concanavalin A-Induced Translocation of Chondroitin Sulfate at the Cell Surface of Mammary Tumor Cells

Abstract

ABSTRACT. The attachment of concanavalin A (Con A) to the cell surface of mammary tumor cells reduced the electrophoretic mobility of the cells at ionic strengths higher than 0.1, but not at strengths lower than 0.03. On chondroitinase-ABC treatment, no further reduction in mobility was observed in the cells treated with Con A at ionic strengths higher than 0.1. However, at strengths lower than 0.03, further reduction in mobility was observed that was as great as that observed with intact cells. In the Con A-treated cells, the amount of chondroitin sulfate removed from the cell surface by the enzyme digestion was larger than that removed from the intact cell surface in spite of the unchanged mobility on electrophoresis. The Con A effect on the distribution of the acidic surface sugars was prevented by a pretreatment with 10-5 M N-ethylenmaleimide, a SH-blocking reagent.The results indicate that the binding of Con A to the cell surface may cause translocation of chondroitin sulfate from the peripheral zone at 0-10A to a deeper zone at 17-24A.