The carbohydrate structure of human fibronectins: A comparison between normal embryonic lung fibroblasts WI-38 and the SV40 virus transformed cell line VA13

Abstract

The carbohydrates of human fibronectin released from non-transformed human fibroblasts WI-38 have been compared with those of fibronectin released from SV40 virus transformed WI-38/VA13 cells and those of fibronectin prepared from human plasma. The majority of the bi-antennary glycopeptides of fibronectin released from WI-38 fibroblasts was not sialylated at the terminal galactosyl residues, but was fucosylated at the coreN-acetylglucosaminyl residue directly linked to a peptide (structure A, below). Most of the minor sialylation detected was linked α2–3 to galactose. In contrast, the majority of the bi-antennary glycopeptides released from the transformed VA13 cells was highly sialylated at the terminal galactosyl residues with both α2–3 and α2–6 linkages, but was only partially fucosylated at the coreN-acetylglucosaminyl residue (structure B, below). This structure was similar to that of the bi-antennary glycopeptide of human plasma fibronectin which was, however, predominantly sialylated with an α2–6 linkage (structure C, below). These human fibronectins, regardless of their source, lack a high molecular weight lactosaminoglycan structure.