Time course of selenium labelling of selenoproteins in Se adequate and Se deficient rats

Conference · Sat Mar 01 04:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5493202

Evenson, J K; Sunde, R A

Column chromatography has identified a number of new selenoproteins. To discriminate between selenoproteins and Se-binding proteins, the authors used SDS-PAGE to remove loosely-bound /sup 75/Se and thus quantitate /sup 75/Se-labelled selenoproteins. +Se (Wayne Lab Blox) and -Se rats (< 0.02 ppm dietary Se) were injected IV with 50 uCi (/sup 75/Se)selenite (0.5 ug Se) and sacrificed 1, 3, 24 or 72 hr later. /sup 75/Se-proteins in various tissues were separated according to subunit molecular weight by SDS-PAGE, and gel slices were counted to determine /sup 75/Se labelling. In +Se plasma, a 55kDa protein was the major /sup 75/Se-protein at 1 and 3 hr; gluathione peroxidase (GSH-Px, 20kDa subunit) was labelled at 24 and 72 hr. In -Se plasma the 55kDa /sup 75/Se-protein was 4-fold higher and GSH-Px /sup 75/Se was reduced. In +Se liver cytosol GSH-Px was the major /sup 75/Se- species at all times; GSH-Px /sup 75/Se was greater in +Se than -Se liver. In +Se and -Se testes, a 17kDa protein was labelled increasingly over 72 hr. Notably, a number of additional /sup 75/Se-proteins were observed, but cycloheximide pretreatment completely blocked /sup 75/Se-labelling of all selenoproteins in both +Se and -Se rats. This study shows that SDS-PAGE can be used to resolve and quantify a number of selenoproteins in addition to GSH-Px. The cycloheximide inhibition of labelling further suggests that these species are true selenoproteins that are labelled only during or immediately after protein synthesis.

• Research Organization: Univ. of Arizona, Tucson
• OSTI ID: 5493202
• Report Number(s): CONF-8604222-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:3
• Country of Publication: United States
• Language: English

Related Subjects

550201 -- Biochemistry-- Tracer Techniques
560305* -- Chemicals Metabolism &amp; Toxicology-- Vertebrates-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BETA DECAY RADIOISOTOPES
BODY
CHROMATOGRAPHY
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
ENZYMES
EVEN-ODD NUCLEI
GLANDS
GONADS
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
LABELLING
LIQUID COLUMN CHROMATOGRAPHY
LIVER
MALE GENITALS
MAMMALS
MOLECULAR WEIGHT
NUCLEI
NUTRITIONAL DEFICIENCY
ORGANIC COMPOUNDS
ORGANS
OXIDOREDUCTASES
PEROXIDASES
PROTEINS
RADIOISOTOPES
RATS
RODENTS
SELENIUM
SELENIUM 75
SELENIUM ISOTOPES
SEMIMETALS
SEPARATION PROCESSES
TESTES
TRACER TECHNIQUES
VERTEBRATES