Synthesis of l-carnitine by microorganisms and isolated enzymes

Jung, Heinrich; Jung, Kirsten; Kleber, Hans‐Peter

doi:10.1007/bfb0007385

Cited by 25 publications

(37 citation statements)

References 106 publications

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“…From this work and a previous study (17) it appears very likely that the glucose repressive effect is mediated via the interaction of CRP with both the regulatory regions of caiF (Fig. 2, Table 3, and data not shown) and the cai and fix operons (7).…”

Section: Discussionmentioning

confidence: 96%

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Identification and characterization of the caiF gene encoding a potential transcriptional activator of carnitine metabolism in Escherichia coli

et al. 1996

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Section: Discussionmentioning

confidence: 96%

“…Consequently, the increasing demand for this compound, particularly in medicine for the treatment of patients suffering from carnitine deficiency syndromes and various heart diseases, has incited the need for searches for microbial and enzymatic synthesis of L-(Ϫ)-carnitine (17).…”

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confidence: 99%

Identification and characterization of the caiF gene encoding a potential transcriptional activator of carnitine metabolism in Escherichia coli

et al. 1996

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“…The function of the carnitine dehydratase in the carnitine pathway is the specific reversible dehydration of L-carnitinyl-CoA to crotonobetainyl-CoA (compare Fig. 6A) (29). Thus, a common feature of 2-arylpropionyl-CoA-epimerase and carnitine dehydratase is the affinity for CoA-linked thioester substrates.…”

Section: Discussionmentioning

confidence: 99%

Molecular Cloning and Expression of a 2-Arylpropionyl-Coenzyme A Epimerase: A Key Enzyme in the Inversion Metabolism of Ibuprofen

et al. 1997

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SUMMARYThe 2-arylpropionic acid derivatives, including ibuprofen, are the most widely used anti-inflammatory analgesic cyclooxygenase inhibitors. The (Ϫ)-R-enantiomer, which is inactive in terms of cyclooxygenase inhibition, is epimerized in vivo via the 2-arylpropionyl-coenzyme A (CoA) epimerase to the cyclooxygenase-inhibiting (ϩ)-S-enantiomer. The molecular biology of the epimerization pathway is largely unknown. To clarify this mechanism, the sequence of the 2-arylpropionyl-CoA epimerase was identified, and the enzyme cloned and expressed. A cDNA clone encoding the 2-arylpropionyl-CoA epimerase was isolated from a rat liver cDNA library. The nucleotide and the deduced amino acid sequence of this enzyme was determined. Significant amino acid sequence similarity was found between the rat epimerase and carnitine dehydratases from Caenorhabditis elegans (41%) and Escherichia coli (27%). A bacterial expression system (E. coli strain M15[pREP4]) was used to express the epimerase protein, representing up to 20 -30% of the total cellular E. coli protein. The expression of the epimerase was confirmed with Western blots using specific antiepimerase antibodies and by measuring the rate of inversion of (R)-ibuprofenoyl-CoA. Northern blot analysis revealed a prominent 1.9-kb mRNA transcript in different rat tissues. In addition to its obvious importance in drug metabolism, the homology of the epimerase with carnitine dehydratases from several species suggests that this protein, which up to now has only been characterized as having a role in drug transformation, has a function in lipid metabolism.

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“…Accumulation of crotonobetaine and y-butyrobetaine in the cytoplasmic solute pools of B. subtik Some micro-organisms can enzymically convert crotonobetaine and y-butyrobetaine into L-carnitine (Jung et al, 1993;Kleber, 1997). We questioned whether B. subtilis could use these compounds as precursors for the synthesis of carnitine, which would then act as a compatible solute.…”

Section: Karnitine Does Not Serve As a Precursor For Glycine Betainementioning

confidence: 99%

Response of Bacillus subtilis to high osmolarity: uptake of carnitine, crotonobetaine and γ-butyrobetaine via the ABC transport system OpuC

Kappes

Bremer

1998

Microbiology

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It was found that low concentrations of the naturally occurring and structurally related betaines L-carnitine, crotonobetaine and y-butyrobetaine conferred a high degree of osmotic tolerance to Bacillus subtilis. Kinetic analysis of ~-[N-rnethyl-~~C]carnitine uptake in cells grown in minimal medium revealed the presence of a high-aff inity transport system with a K, value of 5 pM and a maximum rate of transport (V,,) of 41 nmol min'l (mg protein)''. A rise in medium osmolarity moderately increased the maximum velocity [V,, 71 nmol min'l (mg protein) 'l] of this transport system, but had little effect on its affinity. Growth and transport studies with a set of strains that carried defined mutations in the previously identified glycine betaine transport systems OpuA, OpuC and OpuD allowed the identification of the ATP-binding cassette (ABC) transport system OpuC as the only uptake route for L-carnitine in B. subtilis. Competition experiments with crotonobetaine and ybutyrobetaine revealed that the OpuC system also exhibited a high affinity for these trimethylammonium compounds with Ki values of 6 4 pM. Tracer experiments with radiolabelled L-carnitine and 13C-NMR tracings of cell extracts demonstrated that these betaines are accumulated by B. subtilis in an unmodified form. In contrast, the /?-substituted acylcarnitine esters acetylcarnitine and octanoylcarnitine both functioned as osmoprotectants for B. subtilis but were found to be accumulated as carnitine by the cells. None of these trimethylammonium compounds were used as sole carbon or nitrogen sources. The results thus characterize L-carnitine, crotonobetaine and y-butyrobetaine as effective compatible solutes for B. subtilis and establish a crucial role of the ABC transport system OpuC for the supply of B. subtilis with a variety of osmoprotectants.Keywords : compatible solutes, osmoprotection, ABC transporters, carnitine, acylcarnitines INTRODUCTIONA decrease in the water content of soil imposes a considerable stress on soil-living micro-organisms : water exits from the cells, resulting in decreased turgor and cessation of growth (Miller & Wood, 1996). Bacillus subtilis actively modulates the osmolarity of its cytoplasm under these adverse circumstances through uptake of K+ (Whatmore & Reed, 1990) (Kappes et al., 1996). A glycine betaine transporter closely related to OpuD has recently also been described in the soil bacterium Corynebacterium glutamicum (Peter et al., 1996). The Growth conditions, media and chemicals. The bacterial strains were grown in Spizizen's minimal medium (SMM) with 0 5 % (w/v) glucose as the carbon source and supplemented with L-tryptophan (20 pg ml-') , L-phenylalanine (18 pg ml-l) and a solution of trace elements (Harwood & Archibald, 1990). The osmotic strength of SMM was increased by the addition of NaCl from stock solutions. The osmolarity of growth media was determined with a vapour pressure osmometer (model 5500 ; Wescor) and the osmolarity of SMM, SMM with 0-4M NaCl and SMM with 1.2 M NaCl was 340 mosmol kg-l, 1100 mosm...

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Synthesis of l-carnitine by microorganisms and isolated enzymes

Cited by 25 publications

References 106 publications

Identification and characterization of the caiF gene encoding a potential transcriptional activator of carnitine metabolism in Escherichia coli

Identification and characterization of the caiF gene encoding a potential transcriptional activator of carnitine metabolism in Escherichia coli

Molecular Cloning and Expression of a 2-Arylpropionyl-Coenzyme A Epimerase: A Key Enzyme in the Inversion Metabolism of Ibuprofen

Response of Bacillus subtilis to high osmolarity: uptake of carnitine, crotonobetaine and γ-butyrobetaine via the ABC transport system OpuC

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