Binding of heparan sulphate and heparin to control and virus-transformed cells

A cloned embryonic mouse cell line contained specific cell-surface receptors for heparin and both the number and affinity appeared to be unchanged in a simian-virus-40-transformed subclone. In competitive binding assays heparan sulphate from the control clone was bound preferentially compared to that from the transformed subclone, indicating that the altered sulphation of heparan sulphate from transformed cells results in a lowered affinity for cell-surface receptors. Evidence was obtained suggesting that endogenous proteoglycans were not held at the cell surface by binding to these receptors alone. However the possibility that proteoglycans embedded in the plasma membrane may interact with the receptor has not been ruled out.