Biosynthesis of 5-hydroxy-4-oxo-<scp>L</scp>-norvaline in <i>Streptomyces</i> <i>akiyoshiensis</i>

White, Robert L.; Smith, Kevin C.; DeMarco, Alphonse C.

doi:10.1139/v94-207

Cited by 10 publications

(7 citation statements)

References 11 publications

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“…HPLC separations of diastereomeric, fluorescent isoindole derivatives prepared from o-phthalaldehyde and N-acetylcysteine (Lam, 1986;White et al, 1994) (Table 1). With the exception of serine, the L-amino acids were utilized without a signifi- cant lag period and at a slightly faster rate than their enantiomers (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…The components were dissolved in water, adjusted to pH 7.3-7.4 with 3M NaOH, and autoclaved. Asparagine, citrulline, glutamine, and 5-hydroxy-4-oxo-Lnorvaline (White et al, 1994) were dissolved in potassium phosphate buffer (100raM, pH 7.4, 3 ml), filter sterilized (0.22/zm), and added to sterile peptone medium; all other amino acids were added to the peptone medium prior to autoclaving.…”

Section: Microorganisms Growth Conditions' and Mediamentioning

confidence: 99%

“…Mobile phase used for the separation (100gl) was added, and a 20-#1 portion was injected. The fluorescent isoindole derivatives were separated by gradient elution at a total flow rate of 2.0ml/min on a Nucleosil 5 C18 column (4.6 × 250ram, Phenomenex, Torrance, CA, U.S.A.) (Lain, 1986;White et al, 1994). o-and L-Arginine had retention times of 17.0 and 14.2rain, respectively, when a gradient of composition (min, % acetonitrile) 0.0, 0; 3.0, 5; 13.0, 5; 14.0, 7; 21.0, 7; 23.0, 0 was created by mixing acetonitrile with a solution of acetonitrile (5%) -copper (II) acetate (2.5 raM) -L-proline (5 raM) -ammonium acetate (26 raM), adjusted to pH 7.0 with 5-M NaOH.…”

Section: Enantiomeric Analysis Of Amino Acids' By Hplcmentioning

confidence: 99%

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Utilization ofd-amino acids byFusobacterium nucleatum andFusobacterium varium

1999

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The utilization of D- and L-amino acids with acidic, basic or polar side chains was demonstrated by HPLC. Two species of the anaerobe Fusobacterium utilized D-lysine and the L isomers of glutamate, glutamine, histidine, lysine and serine. Only F. varium used L-arginine, D-glutamate and D-serine as substrates, whereas F. nucleatum specifically utilized D-histidine and D-glutamine. D-Glutamate accumulated in F. nucleatum cultures supplemented with D-glutamine, and ornithine was detected when either DL- or L-arginine was included in F. varium cultures. Based on literature precedents, D-glutamate and D-histidine are isomerized to their L isomers prior to degradation, but separate catabolic pathways are possible for each enantiomer of lysine and serine.

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Section: Resultsmentioning

confidence: 99%

Section: Microorganisms Growth Conditions' and Mediamentioning

confidence: 99%

Section: Enantiomeric Analysis Of Amino Acids' By Hplcmentioning

confidence: 99%

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Utilization ofd-amino acids byFusobacterium nucleatum andFusobacterium varium

1999

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“…Such a combination therapy would target a biosynthetic pathway that is conserved in fungi but not in mammals. The natural compound 5-hydroxy-4-oxonorvaline (HON), a toxic amino acid produced by Streptomyces akiyoshiensis, is a very efficient inhibitor of homoserine dehydrogenase (40,82,87,88). HON inhibits growth by blocking synthesis of homoserine, and it has shown activity against different fungal organisms (87).…”

Section: Discussionmentioning

confidence: 99%

FKBP12 Controls Aspartate Pathway Flux in Saccharomyces cerevisiae To Prevent Toxic Intermediate Accumulation

et al. 2004

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FKBP12 is a conserved member of the prolyl-isomerase enzyme family and serves as the intracellular receptor for FK506 that mediates immunosuppression in mammals and antimicrobial actions in fungi. To investigate the cellular functions of FKBP12 in Saccharomyces cerevisiae, we employed a high-throughput assay to identify mutations that are synthetically lethal with a mutation in the FPR1 gene, which encodes FKBP12. This screen identified a mutation in the HOM6 gene, which encodes homoserine dehydrogenase, the enzyme catalyzing the last step in conversion of aspartic acid into homoserine, the common precursor in threonine and methionine synthesis. Lethality of fpr1 hom6 double mutants was suppressed by null mutations in HOM3 or HOM2, encoding aspartokinase and aspartate ␤-semialdehyde dehydrogenase, respectively, supporting the hypothesis that fpr1 hom6 double mutants are inviable because of toxic accumulation of aspartate ␤-semialdehyde, the substrate of homoserine dehydrogenase. Our findings also indicate that mutation or inhibition of FKBP12 dysregulates the homoserine synthetic pathway by perturbing aspartokinase feedback inhibition by threonine. Because this pathway is conserved in fungi but not in mammals, our findings suggest a facile route to synergistic antifungal drug development via concomitant inhibition of FKBP12 and Hom6.Prolyl isomerases are widely conserved, ubiquitous enzymes that catalyze cis-trans isomerization of peptidyl-prolyl bonds, a reaction that can be rate limiting for protein folding. Founding members of this group of enzymes are cyclophilin A, previously identified as the cyclosporine A receptor (25,31,75), and the structurally unrelated enzyme FK506 binding protein FKBP12 (35). A third family of prolyl isomerases, known as the parvulins, was discovered for bacteria (60, 61) and later was found to be conserved in many other organisms.Cyclophilin A and FKBP12 mediate the immunosuppressive effects of cyclosporine A and FK506 in mammals by forming complexes with these drugs that bind to and inhibit the functions of calcineurin in T-cell activation (for a review, see reference 68). FKBP12 is also the receptor for the drug rapamycin, and the FKBP12-rapamycin complex inhibits the functions of the Tor proteins (36, 44). Both cyclophilin A and FKBP12 are conserved in budding yeast (where they are encoded by the CPR1 and FPR1 genes, respectively) and mediate calcineurin inhibition by cyclosporine A and FK506 (11,26,30,37,38,52,55,78,83) and Tor inhibition by rapamycin (36, 44). Saccharomyces cerevisiae expresses seven other cyclophilins (Cpr2 to Cpr8), three other FKBPs (Fpr2 to Fpr4), and a single parvulin (Ess1) (for a recent review, see reference 6).With the exception of Ess1, all yeast prolyl isomerases are dispensable for growth (18,32,34). However, cyclophilin A does become essential in cells compromised for Ess1 function, suggesting a functional overlap between these two structurally unrelated prolyl isomerases (4). Thus far, the endogenous functions that have been defined for these prot...

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“…The F . varium cells collected in the time‐course experiment were extracted with 80% aqueous ethanol [34]; HPLC analysis showed no intracellular accumulation of glutamate, consistent with the degradation of both d ‐ and l ‐glutamate. F. varium cultures supplemented with d‐ [3‐ 13 C]glutamate (Table 1, Expt 7) yielded 13 C‐enriched acetate (1.5% at C2) and butyrate (5.3% and 5.4% at C2 and C4, respectively).…”

Section: Resultsmentioning

confidence: 99%

Glutamate racemization and catabolism inFusobacterium varium

2011

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The pathways of glutamate catabolism in the anaerobic bacterium Fusobacterium varium, grown on complex, undefined medium and chemically defined, minimal medium, were investigated using specifically labelled 13C‐glutamate. The metabolic end‐products acetate and butyrate were isolated from culture fluids and derivatized for analysis by nuclear magnetic resonance and mass spectrometry. On complex medium, labels from l‐[1‐13C]glutamate and l‐[4‐13C]glutamate were incorporated into C1 of acetate and equally into C1/C3 of butyrate, while label derived from l‐[5‐13C]glutamate was not incorporated. The isotopic incorporation results and the detection of glutamate mutase and 3‐methylaspartate ammonia lyase in cell extracts are most consistent with the methylaspartate pathway, the best known route of glutamate catabolism in Clostridium species. When F. varium was grown on defined medium, label from l‐[4‐13C]glutamate was incorporated mainly into C4 of butyrate, demonstrating a major role for the hydroxyglutarate pathway. Upon addition of coenzyme B12 or cobalt ion to the defined medium in replicate experiments, isotope was located equally at C1/C3 of butyrate in accord with the methylaspartate pathway. Racemization of d‐glutamate and subsequent degradation of l‐glutamate via the methylaspartate pathway are supported by incorporation of label into C2 of acetate and equally into C2/C4 of butyrate from d‐[3‐13C]glutamate and the detection of a cofactor‐independent glutamate racemase in cell extracts. Together the results demonstrate a major role for the methylaspartate pathway of glutamate catabolism in F. varium and substantial participation of the hydroxyglutarate pathway when coenzyme B12 is not available.

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Biosynthesis of 5-hydroxy-4-oxo-L-norvaline in Streptomyces akiyoshiensis

Cited by 10 publications

References 11 publications

Utilization ofd-amino acids byFusobacterium nucleatum andFusobacterium varium

Utilization ofd-amino acids byFusobacterium nucleatum andFusobacterium varium

FKBP12 Controls Aspartate Pathway Flux in Saccharomyces cerevisiae To Prevent Toxic Intermediate Accumulation

Glutamate racemization and catabolism inFusobacterium varium

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