Serine incorporation into the selenocysteine moiety of glutathione peroxidase

Journal Article · Thu Jan 15 00:00:00 EST 1987 · J. Biol. Chem.; (United States)

OSTI ID:6704858

Sunde, R A; Evenson, J K

The selenium in mammalian glutathione peroxidase is present as a selenocysteine ((Se)Cys) moiety incorporated into the peptide backbone 41-47 residues from the N-terminal end. To study the origin of the skeleton of the (Se)Cys moiety, we perfused isolated rat liver with /sup 14/C- or /sup 3/H-labeled amino acids for 4 h, purified the GSH peroxidase, derivatized the (Se)Cys in GSH peroxidase to carboxymethylselenocysteine ((Se)Cys(Cm)), and determined the amino acid specific activity. Perfusion with (/sup 14/C)cystine resulted in (/sup 14/C)cystine incorporation into GSH peroxidase without labeling (Se)Cys(Cm), indicating that cysteine is not a direct precursor for (Se)Cys. (/sup 14/C)Serine perfusion labeled serine, glycine (the serine hydroxymethyltransferase product), and (Se)Cys(Cm) in purified GSH peroxidase, whereas (3-3H)serine perfusion only labeled serine and (Se)Cys(Cm), thus demonstrating that the (Se)Cys in GSH peroxidase is derived from serine. The similar specific activities of serine and (Se)Cys(Cm) strongly suggest that the precursor pool of serine used for (Se) Cys synthesis is the same or similar to the serine pool used for acylation of seryl-tRNAs.

• Research Organization: Univ. of Arizona, Tucson
• OSTI ID: 6704858
• Journal Information: J. Biol. Chem.; (United States), Vol. 2
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
SELENIUM
UPTAKE
SERINE
BIOCHEMISTRY
AMINO ACIDS
CARBON 14 COMPOUNDS
CYSTEINE
GLUTATHIONE
LIVER
PEROXIDASES
RATS
TRACER TECHNIQUES
TRANSFER RNA
TRITIUM COMPOUNDS
ANIMALS
BODY
CARBOXYLIC ACIDS
CHEMISTRY
DIGESTIVE SYSTEM
DRUGS
ELEMENTS
ENZYMES
GLANDS
HYDROXY ACIDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
NUCLEIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
OXIDOREDUCTASES
PEPTIDES
POLYPEPTIDES
PROTEINS
RADIOPROTECTIVE SUBSTANCES
RNA
RODENTS
SEMIMETALS
THIOLS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques