Biosynthesis of transhydrogenase in vitro and in vivo

Conference · Thu May 01 04:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5207596

Lubin, I M; Wu, L N.Y.; Fisher, R R

Mitochondrial pyridine dinucleotide transhydrogenase has been shown previously to be synthesized in rat liver as a larger precursor (..delta..Mr=2000). Further studies on processing of precursor were investigated in isolated rat liver mitochondria, the soluble matrix fraction and primary cultures of hepatocytes. Incubation of the /sup 35/(S) methionine labeled translation mixture with the isolated rat liver mitochondria showed that mature transhydrogenase was associated with the mitochondrial membrane at a protease resistant location. When the translation mixture was incubated with the soluble matrix fraction, the precursor was progressively converted to the mature size in 60 minutes at 30/sup 0/C. Leupeptin, 1,10 phenanthroline and EDTA were effective in inhibiting the soluble matrix processing activity. Also, rhodamine 123, a mitochondrial specific dye, has been found to inhibit conversion of the transhydrogenase precursor to mature enzyme in vivo. When primary cultures of rat hepatocytes were pulsed for 10 minutes with /sup 35/(S) methionine in the presence of rhodamine 123 and fractionated into cytosolic and membranous components, the precursor was found almost entirely within the cytosolic fraction with little or no mature transhydrogenase found in either fraction. Subsequent pulse-chase experiments performed in the presence of rhodamine 123 showed transhydrogenase precursor to have a T/sub 1/2/ of 10-15 minutes in the cytosol.

• Research Organization: Univ. of South Carolina, Columbia
• OSTI ID: 5207596
• Report Number(s): CONF-8606151-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:6
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOSYNTHESIS
BODY
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CELL CULTURES
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
DRUGS
ENZYMES
EVEN-ODD NUCLEI
GLANDS
HYDROGENASES
IN VITRO
IN VIVO
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
LIPOTROPIC FACTORS
LIVER
MAMMALS
METHIONINE
MITOCHONDRIA
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANOIDS
ORGANS
OXIDOREDUCTASES
RADIOISOTOPES
RATS
RODENTS
SULFUR 35
SULFUR ISOTOPES
SYNTHESIS
TRACER TECHNIQUES
VERTEBRATES