Characterization of thyroidal glutathione reductase

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6612843

Raasch, R J

Glutathione levels were determined in bovine and rat thyroid tissue by enzymatic conjugation with 1-chloro-2,4-dinitrobenzene using glutathione S-transferase. Bovine thyroid tissue contained 1.31 {+-} 0.04 mM reduced glutathione (GSH) and 0.14 {+-} 0.02 mM oxidized glutathione (GSSG). In the rat, the concentration of GSH was 2.50 {+-} 0.05 mM while GSSG was 0.21 {+-} 0.03 mM. Glutathione reductase (GR) was purified from bovine thyroid to electrophoretic homogeneity by ion exchange, affinity and molecular exclusion chromatography. A molecular weight range of 102-109 kDa and subunit size of 55 kDa were determined for GR. Thyroidal GR was shown to be a favoprotein with one FAD per subunit. The Michaelis constants of bovine thyroidal GR were determined to be 21.8 {mu}M for NADPH and 58.8 {mu}M for GSSG. The effect of thyroid stimulating hormone (TSH) and thyroxine (T{sub 4}) on in vivo levels of GR and glucose 6-phosphate dehydrogenase were determined in rat thyroid homogenates. Both enzymes were stimulated by TSH treatment and markedly reduced following T{sub 4} treatment. Lysosomal hydrolysis of ({sup 125}I)-labeled and unlabeled thyroglobulin was examined using size exclusion HPLC.

• Research Organization: North Dakota State Univ., Fargo, ND (USA)
• OSTI ID: 6612843
• Country of Publication: United States
• Language: English

Related Subjects

550201 -- Biochemistry-- Tracer Techniques
560300* -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
AROMATICS
BETA DECAY RADIOISOTOPES
BIOSYNTHESIS
BODY
CATTLE
CHEMICAL COMPOSITION
CHLORINATED AROMATIC HYDROCARBONS
CHROMATOGRAPHY
DAYS LIVING RADIOISOTOPES
DOMESTIC ANIMALS
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ENDOCRINE GLANDS
ENZYMES
FRACTIONATION
GLANDS
GLUTATHIONE
HALOGENATED AROMATIC HYDROCARBONS
HORMONES
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LIQUID COLUMN CHROMATOGRAPHY
MAMMALS
METABOLISM
MOLECULAR WEIGHT
NITRO COMPOUNDS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
OXIDOREDUCTASES
PEPTIDE HORMONES
PEPTIDES
POLYPEPTIDES
PROTEINS
RADIOISOTOPES
RADIOPROTECTIVE SUBSTANCES
RATS
RODENTS
RUMINANTS
SEPARATION PROCESSES
SYNTHESIS
THYROID
THYROID HORMONES
TRACER TECHNIQUES
VERTEBRATES