Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.4.1.2 (acetyl-CoA carboxylase)
 2,876 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Biotin carboxylases in mammalian cells are regulatory enzymes in lipogenesis and gluconeogenesis. In this study, endogenous biotin in skeletal and cardiac muscle was detected using avidin conjugated with alkaline phosphatase and applied in high concentrations to muscle sections. The avidin binding was subsequently visualized by histochemical demonstration of the alkaline phosphatase activity. All cardiac muscle cells showed high affinity for avidin with only the nuclei and the intercalated discs remaining unstained. In skeletal muscle a diffuse reaction could be detected in the sarcoplasm of the muscle fibres. A granular reaction was noted in the same fibres that showed activity for succinic dehydrogenase. The specificity of the coloured reaction product in the muscle sections was investigated and is suggested to be caused by avidin binding to biotin moieties in mitochondria and the cytosol. Mitochondrial and cytosolic preparations of skeletal muscle were electrophoresed in sodium dodecyl sulphate gels. After blotting and incubation with conjugated avidin, two bands with molecular weights of 75 kDa and 130 kDa respectively were evident in the mitochondrial preparation. It is suggested that the 75-kDa band represents comigration of the biotin-containing subunits of propionyl-CoA carboxylase and methylcrotonyl-CoA carboxylase. The 130-kDa band may represent the biotin-containing pyruvate carboxylase. In the cytosolic preparation a 270-kDa band was stained in blots that had been incubated with conjugated avidin; this band is suggested to represent acetyl-CoA carboxylase. A 190-kDa cytosolic band might be a cleavage product of acetyl-CoA carboxylase. We propose that using alkaline phosphatase-conjugated avidin it is possible to detect the mitochondrial and cytosolic biotin-dependent carboxylases in striated muscle.
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PMID:Biotin carboxylases in mitochondria and the cytosol from skeletal and cardiac muscle as detected by avidin binding. 816 85

The pyruvate dehydrogenase complex from pea (Pisum sativum L.) mitochondria was purified 23-fold by high speed centrifugation and glycerol gradient fractionation. The complex had a s(20,w) of 47.5S but this is a minimal value since the complex is unstable. The complex is specific for NAD(+) and pyruvate; NADP(+) and other keto acids give no reaction. Mg(2+), thiamine pyrophosphate, and cysteine are also required for maximal activity. The pH optimum for the complex was between 6.5 and 7.5.Continuous sucrose density gradients were used to separate castor bean (Ricinus communis L.) endosperm proplastids from mitochondria. Pyruvate dehydrogenase complex activity was found to be coincident with the proplastid peak on all of the gradients. Some separation of proplastids and mitochondria could be achieved by differential centrifugation and the ratios of the activities of the pyruvate dehydrogenase complex to succinic dehydrogenase and acetyl-CoA carboxylase to succinic dehydrogenase were consistent with both the pyruvate dehydrogenase complex and acetyl-CoA carboxylase being present in the proplastid. The proplastid fraction has to be treated with a detergent, Triton X-100, before maximal activity of the pyruvate dehydrogenase complex activity is expressed, indicating that it is bound in the organelle. The complex had a sharp pH optimum of 7.5. The complex required added Mg(2+), cysteine, and thiamine pyrophosphate for maximal activity but thiamine pyrophosphate was inhibitory at higher concentrations.
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PMID:Pyruvate dehydrogenase complex from higher plant mitochondria and proplastids. 1665 53