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Repression of acetyl-coenzyme A carboxylase by unsaturated fatty acids: relationship to coenzyme repression.
- Source :
-
Journal of bacteriology [J Bacteriol] 1970 Oct; Vol. 104 (1), pp. 171-6. - Publication Year :
- 1970
-
Abstract
- It has been reported that the level of d-biotin in the growth medium of Lactobacillus plantarum regulates the synthesis of apoacetyl-coenzyme A (CoA) carboxylase; high levels cause repression, and deficient levels effect derepression. In this study, evidence has been obtained which suggests that coenzyme repression by biotin is an indirect effect; i.e., biotin regulates the synthesis of unsaturated fatty acids which are the true repressors of the acetyl-CoA carboxylase. This was observed in an experiment in which long-chain unsaturated fatty acids were added to media containing deficient, sufficient, or excess levels of d-biotin. In every case, independently of the biotin concentration for growth, the unsaturated fatty acids caused a severe repression of the carboxylase. Saturated fatty acids were without effect. The level of oleic acid required to give maximal repression was 50 mug/ml. The free fatty acids had no adverse effect on the activity of the cell-free extracts nor on the permeation of d-biotin into the cell. Saturated and unsaturated fatty acids decreased the rate of holocarboxylase formation from d-biotin and the apoacetyl-CoA carboxylase in the extracts. It is concluded that there are at least three mechanisms that control the acetyl-CoA carboxylase in this organism: (i) indirect coenzyme repression by d-biotin, (ii) repression by unsaturated fatty acids, and (iii) regulation of the activity of the holocarboxylase synthetase by both saturated and unsaturated fatty acids.
Details
- Language :
- English
- ISSN :
- 0021-9193
- Volume :
- 104
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Journal of bacteriology
- Publication Type :
- Academic Journal
- Accession number :
- 5473885
- Full Text :
- https://doi.org/10.1128/jb.104.1.171-176.1970