Phosphorylated high mannose-type and hybrid-type oligosaccharide chains of human thyroglobulin isolated from malignant thyroid tissue.

Structures of anionic oligosaccharides released by endo-beta-N-acetylglucosaminidase H from human thyroglobulin (19 S) purified from normal and malignant (papillary carcinoma) thyroid tissues were studied by sequential exoglycosidase digestion and lectin affinity chromatography. It was revealed that sialylated hybrid-type oligosaccharides were present in thyroglobulin from normal thyroid tissue, whereas, in the case of thyroglobulin from malignant thyroid tissue, phosphorylated high-mannose type and hybrid-type oligosaccharides each containing one phosphate group in a diester linkage were present instead of sialylated oligosaccharides. The possible meaning of the phosphorylated oligosaccharides was discussed in relation to the low thyroglobulin content in malignant thyroid tissue.