Mycolic acid synthesis by Mycobacterium aurum cell-free extracts
| Autor: | Gilbert Lanéelle, Marie-Antoinette Lanéelle, Charlotte Lacave |
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| Rok vydání: | 1990 |
| Předmět: |
Time Factors
Chemical Phenomena Stereochemistry Biophysics Acetates Buffers Biochemistry Mycobacterium aurum Cofactor Mycobacterium Mycolic acid Cell-free system Palmitic acid chemistry.chemical_compound Endocrinology Biosynthesis chemistry.chemical_classification Cell-Free System biology biology.organism_classification Chemistry Enzyme Mycolic Acids chemistry Carboxylation biology.protein |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism. 1042:315-323 |
| ISSN: | 0005-2760 |
| DOI: | 10.1016/0005-2760(90)90159-u |
| Popis: | The first cell-free system capable of synthesizing whole mycolic acids: (R1CH(OH)CH(R2)COOH, with 60 to 90 carbon atoms) from [1-14C]acetate is described and preliminary investigations into some of its requirements and properties are reported. Biosynthetic activity for mycolic acids occurred in an insoluble fraction (40 000 × g pellet) from disrupted cells of Mycobacterium aurum (ATCC 23366-type strain); it produced mycolic acids, but a very small amount of non-hydroxylated fatty acids. The predominant product was unsaturated mycolic acid (type I), while oxo- (type IV) and dicarboxy- (type VI) mycolic acids were synthesized to a lesser extent. When |1-14C|palmitic acid was used as a marker, no labelled mycolic acid was detected. The reaction required a divalent cation (Mg2+ or Mn2+), KHCO3 and O2. Neither CoA, NADH, NADPH nor ATP were necessary, but CoA rather increased the synthesis of non-hydroxylated fatty acids. Glucose or trehalose were not required. Avidin inhibited the biosynthesis of the three types of mycolic acid indicating the presence of a biotin-requiring enzyme in the reaction sequence and therefore a carboxylation step, but citrate had no allosteric effect. Iodoacetamide inhibited the system. These first data are in favor of a complex multienzyme system. |
| Databáze: | OpenAIRE |
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