Biosynthesis of sulfated asparagine-linked complex carbohydrate units of calf thyroglobulin

Journal Article · Fri Jul 01 00:00:00 EDT 1988 · Endocrinology; (United States)

OSTI ID:6954445

Spiro, M J; Spiro, R G

Thyroglobulin from colloid as well as from membrane fractions became radiolabeled upon incubation of calf thyroid slices with (35S)sulfate. The identity of the sulfate-labeled molecule was established by immunoprecipitation, polyacrylamide gel electrophoresis, Bio-Gel A-5m filtration, and DEAE-cellulose chromatography. Size analysis by gel filtration of (35S)glycopeptides and hydrazine-released oligosaccharides indicated that the sulfate was primarily located in the complex (unit B) carbohydrate units of thyroglobulin. Moreover, although (35S)sulfate-labeled oligosaccharides were cleaved by N-glycanase to the same extent as those labeled with (3H)mannose, they were not released by endo-beta-N-acetylglucosaminidase under conditions that led to the complete removal of polymannose carbohydrate (unit A). The failure of 35S-labeled glycopeptides and oligosaccharides to bind to immobilized Concanavalin-A indicated that the sulfate residues in calf thyroglobulin are located in carbohydrate units with three or more branches. No evidence for the occurrence of tyrosine sulfate was found upon examination of Pronase digests of radiolabeled thyroglobulin, and chemical analyses excluded the presence of this amino acid down to a level of 0.5 residues/polypeptide subunit. Studies with density gradient-separated membrane fractions as well as with puromycin indicated that sulfate addition is a late event in thyroglobulin biosynthesis which occurs in the Golgi compartment. Furthermore, it was observed that the nondimerized thyroglobulin subunit was much less sulfate labeled than the mature molecule.

• Research Organization: Harvard Medical School, Boston, MA (USA)
• OSTI ID: 6954445
• Journal Information: Endocrinology; (United States), Vol. 123:1
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
THYROGLOBULIN
BIOSYNTHESIS
ASPARAGINE
BIOCHEMICAL REACTION KINETICS
CALVES
CHROMATOGRAPHY
CONCANAVALIN
ELECTROPHORESIS
GLUCOSE
GLYCOSYL HYDROLASES
IN VITRO
LEUCINE
MANNOSE
OLIGOSACCHARIDES
SULFATES
SULFUR 35
TRACER TECHNIQUES
TRITIUM COMPOUNDS
TRYPSIN
AGGLUTININS
ALDEHYDES
AMIDES
AMINO ACIDS
ANIMALS
ANTIBODIES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBOHYDRATES
CARBOXYLIC ACIDS
CATTLE
DAYS LIVING RADIOISOTOPES
DOMESTIC ANIMALS
ENZYMES
EVEN-ODD NUCLEI
GLOBULINS
HEMAGGLUTININS
HEXOSES
HYDROLASES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LABELLED COMPOUNDS
LECTINS
LIGHT NUCLEI
MAMMALS
MONOSACCHARIDES
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
PEPTIDE HYDROLASES
PROTEINS
RADIOISOTOPES
REACTION KINETICS
RUMINANTS
SACCHARIDES
SEPARATION PROCESSES
SERINE PROTEINASES
SULFUR COMPOUNDS
SULFUR ISOTOPES
SYNTHESIS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques