The interaction of heparan sulfate with protein ligands depends on unique oligosaccharide
sequences containing iduronic acid (IdUA), N-sulfated glucosamine residues, and O-
sulfated sugars. To study the role of O-sulfation in greater detail, we isolated a Chinese
hamster ovary cell mutant defective in 2-O-sulfation of iduronic acid. The mutant, pgsF-17,
was identified by a colony blotting assay in which colonies of mutagen-treated cells were
replica plated to two disks of polyester cloth. One disk was blotted with 125 I-labeled basic …