Acetyl Coenzyme A Carboxylase

作者：Philip W. Majerus, Elisabeth Kilburn · 发表于：Journal of Biological Chemistry · 年份：1969 · DOI：10.1016/s0021-9258(18)63531-8 · 被引用次数：218 · 研究领域：Biotin and Related Studies、Muscle metabolism and nutrition、Neurological diseases and metabolism

The roles of synthesis and degradation in the regulation of acetyl coenzyme A carboxylase levels in rat liver following fasting and fat-free feeding have been studied. Antibodies prepared to homogeneous chicken liver acetyl-CoA carboxylase were shown to cross-react with rat liver acetyl-CoA carboxylase. Enzyme from both species was totally inactivated as well as precipitated by this antibody preparation. Furthermore, quantitative precipitin curves and equivalence point determinations indicated that enzymes from the two species were precipitated in equal quantity by antibody and that the two enzymes had identical turnover numbers. It was also shown that disaggregated, aggregated, and palmityl-CoA-treated enzyme were all equally precipitated by antibody. Immunological analysis of crude homogenates of rat liver from animals treated with different diets, which had specific activities for acetyl-CoA carboxylase varying over 25-fold indicated that there was a constant amount of immunologically precipitable enzyme per unit of enzyme activity. The changes in acetyl-CoA carboxylase activity measured after dietary alteration result from changes in the enzyme content of liver rather than from activation or inhibition of preformed enzyme. The relative rates of acetyl-CoA carboxylase synthesis were determined by quantitative precipitation of the enzyme by antibody after pulse labeling with 3H-leucine. There was a 5- to 10-fold increase in the rate of enzyme synthesis after fat-free feedin...