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Longer-term regulation of branched-chain-2-oxoacid dehydrogenase complex studied in rat hepatocytes in culture
- Source :
- The Biochemical journal. 257(1)
- Publication Year :
- 1989
-
Abstract
- The effect of protein-free diet to decrease liver activity of branched-chain (-2-oxoacid) dehydrogenase (BCD) complex (active form) and increase BCD kinase activity was unaffected by preparation of hepatocytes, but partially reversed by 25 h of culture of hepatocytes in medium 199. Activation of BCD complex preceded loss of BCD kinase. The effect of culture on BCD complex was completely prevented by omission of branched-chain amino acids and partially prevented by 1 mM-alpha-cyano-4-hydroxycinnamate or 0.2 mM-pyruvate/2 mM-lactate. Protein-free diet decreased plasma branched-chain amino and oxo (‘keto’) acids and increased plasma pyruvate and lactate. It is concluded: (1) that branched-chain amino acids are involved directly in regulation of activities of BCD complex and BCD kinase; (2) that mitochondrial uptake of branched-chain oxo acids is necessary for regulation of BCD complex activity; and (3) that the stable increase in BCD kinase may function as a hysteresis mechanism.
- Subjects :
- animal structures
Dehydrogenase
Mitochondria, Liver
Biology
Biochemistry
3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)
chemistry.chemical_compound
Multienzyme Complexes
Animals
Kinase activity
Molecular Biology
Cells, Cultured
chemistry.chemical_classification
Kinase
Ketone Oxidoreductases
Cell Biology
Keto Acids
Amino acid
Rats
chemistry
Oxoacid
embryonic structures
Dietary Proteins
Dehydrogenase complex
Protein Kinases
Function (biology)
Amino Acids, Branched-Chain
Research Article
Subjects
Details
- ISSN :
- 02646021
- Volume :
- 257
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- The Biochemical journal
- Accession number :
- edsair.doi.dedup.....eab6142792230cda38948125df7a4d77