The amidases from a Brevibacterium strain: Study and applications

Maestracci, M.; Bui, K.; Thiéry, Alain; Arnaud, A.; Galzy, P.

doi:10.1007/bfb0047945

Cited by 19 publications

(20 citation statements)

References 123 publications

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“…The presence of discrete formamidase (formamide amidohydrolase, EC 3.5.1.49) with narrow substrate specificity, in addition to an aliphatic amidase, has been reported in M. methylotrophus (Wyborn et al, 1996), Alcaligenes eutrophus (Friedrich and Mitrenga, 1981) and Rhodococcus sp. R312 (Maestracci et al, 1988). No cross-substrate recognition between the H. pylori aliphatic amidase and its very potent urease was observed.…”

Section: Discussionmentioning

confidence: 97%

Identification and characterization of an aliphatic amidase in Helicobacter pylori

Skouloubris

Labigne

Reuse

1997

Molecular Microbiology

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SummaryWe report, for the first time, the presence in Helicobacter pylori of an aliphatic amidase that, like urease, contributes to ammonia production. Aliphatic amidases are cytoplasmic acylamide amidohydrolases (EC 3.5.1.4) hydrolysing short-chain aliphatic amides to produce ammonia and the corresponding organic acid. The finding of an aliphatic amidase in H. pylori was unexpected as this enzyme has only previously been described in bacteria of environmental (soil or water) origin. The H. pylori amidase gene amiE (1017 bp) was sequenced, and the deduced amino acid sequence of AmiE (37 746 Da) is very similar (75% identity) to the other two sequenced aliphatic amidases, one from Pseudomonas aeruginosa and one from Rhodococcus sp. R312. Amidase activity was measured as the release of ammonia by sonicated crude extracts from H. pylori strains and from recombinant Escherichia coli strains overproducing the H. pylori amidase. The substrate specificity was analysed with crude extracts from H. pylori cells grown in vitro; the best substrates were propionamide, acrylamide and acetamide. Polymerase chain reaction (PCR) amplification of an internal amiE sequence was obtained with each of 45 different H. pylori clinical isolates, suggesting that amidase is common to all H. pylori strains. A H. pylori mutant (N6-836) carrying an interrupted amiE gene was constructed by allelic exchange. No amidase activity could be detected in N6-836. In a N6-urease negative mutant, amidase activity was two-to threefold higher than in the parental strain N6. Crude extracts of strain N6 slowly hydrolysed formamide. This activity was affected in neither the amidase negative strain (N6-836) nor a double mutant strain deficient in both amidase and urease activities, suggesting the presence of an independent discrete formamidase in H. pylori. The existence of an aliphatic amidase, a correlation between the urease and amidase activities and the possible presence of a formamidase indicates that H. pylori has a large range of possibilities for intracellular ammonia production.

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Section: Discussionmentioning

confidence: 97%

Identification and characterization of an aliphatic amidase in Helicobacter pylori

Skouloubris

Labigne

Reuse

1997

Molecular Microbiology

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“…Amide compounds which act as substrates and inducers of known amidase (acetamide and lactamide for the amidase of Pseudomonas aeruginosa [11,13]; benzamide for that of Aspergillus nidulans [9]; cyclic ureides for dihydropyrimidinase; ammonium chloride and L-glutamine for -amidase) were less effective or somewhat repressive on the production of halfamidase (Table 1).…”

Section: Resultsmentioning

confidence: 99%

A Novel Amidase (Half-Amidase) for Half-Amide Hydrolysis Involved in the Bacterial Metabolism of Cyclic Imides

Soong

Ogawa

Shimizu

2000

Appl Environ Microbiol

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A novel amidase involved in bacterial cyclic imide metabolism was purified from Blastobacter sp. strain A17p-4. The enzyme physiologically functions in the second step of cyclic imide degradation, i.e., the hydrolysis of monoamidated dicarboxylates (half-amides) to dicarboxylates and ammonia. Enzyme production was enhanced by cyclic imides such as succinimide and glutarimide but not by amide compounds which are conventional substrates and inducers of known amidases. The purified amidase showed high catalytic efficiency toward half-amides such as succinamic acid (K m ‫؍‬ 6.2 mM; k cat ‫؍‬ 5.76 s ؊1) and glutaramic acid (K m ‫؍‬ 2.8 mM; k cat ‫؍‬ 2.23 s ؊1 ). However, the substrates of known amidases such as short-chain (C 2 to C 4 ) aliphatic amides, long-chain (above C 16 ) aliphatic amides, amino acid amides, aliphatic diamides, ␣-keto acid amides, N-carbamoyl amino acids, and aliphatic ureides were not substrates for the enzyme. Based on its high specificity toward half-amides, the enzyme was named half-amidase. This half-amidase exists as a monomer with an M r of 48,000 and was strongly inhibited by heavy metal ions and sulfhydryl reagents.A variety of cyclic amide-metabolizing systems occur in nature and play important roles in pyrimidine and purine metabolism, amino acid metabolism (histidine degradation), antibiotic metabolism (␤-lactam decomposition), creatinine degradation, etc.Cyclic imide is a kind of cyclic amide, and the metabolism of cyclic imides has been studied in relation to the detoxification of the antiepileptic agents ethotoin and phensuximide in mammals (3,36). During the course of a study on cyclic amide transformation for hydantoin from the practical viewpoint of industrial D-amino acid production, we recently found that microorganisms also transform cyclic imides (21,(24)(25)(26)(27). Microbial transformation of cyclic imides found in the bacterium Blastobacter sp. strain A17p-4 (22) involves ring opening of cyclic imide to monoamidated dicarboxylate (half-amide) catalyzed by imidase (23), half-amide hydrolysis to dicarboxylate catalyzed by amidase, and subsequent trichloroacetic acid (TCA) cycle-like reactions (Fig. 1). The reactions and enzymes (imidase and amidase) involved in the metabolism have practical potential for production of organic acids from cyclic imides or their metabolites and for fine enzymatic synthesis of useful compounds. For example, pyruvate, an effective precursor in the synthesis of various drugs and agrochemicals, was produced from succinimide or its metabolites (especially fumarate, a cheap material) through cyclic imide-transforming pathway ( Fig. 1A and B) (28). Imidase was applied for the regiospecific synthesis of useful half-amide (3-carbamoyl-␣-picolinic acid, an intermediate for herbicide) from a cyclic imide (2,3-pyridinedicarboximide) (J. Ogawa, M. Ito, T. Segawa, C.-L. Soong, and S. Shimizu, Abstr. Annu. Meet. '99 Soc. Biosci. Bioeng., abstr. 182, 1999 [in Japanese]). Amidase also has a potential for the chiral resolution of dicarboxylates through the ...

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“…Like other purified and immobilized amidases, G. pallidus BTP-5x MTCC 9225 exhibit maximum acyl transferase activity at neutral pH [11][12][13][14][15][16]. The immobilized purified amidase of Rhodococcus sp.…”

Section: Discussionmentioning

confidence: 99%

Biotransformation of Acetamide to Acetohydroxamic Acid at Bench Scale Using Acyl Transferase Activity of Amidase of Geobacillus pallidus BTP-5x MTCC 9225

Sharma

Bhalla

2011

Indian J Microbiol

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The bioprocess employing acyl transferase activity of intracellular amidase of Geobacillus pallidus BTP-5x MTCC 9225 was harnessed for the synthesis of pharmaceutically important acetohydroxamic acid. G. pallidus BTP-5x exhibited highest acyl transferase activity with acetamide: hydroxylamine in ratio of 1:5 in 0.1 M NaH 2 PO 4 /Na 2 HPO 4 buffer (pH 7.5) at 65°C. In one liter fed-batch reaction containing 1:5 ratio of two substrates total of eight feedings of 0.05 M/20 min of acetamide were made and it was found that maximum acetohydroxamic production was achieved at 3:5 ratios of substrate and cosubstrate. In 1 l bench scale batch reaction containing 0.3 M acetamide, 0.5 M hydroxylamine in 0.1 M NaH 2 PO 4 /Na 2 HPO 4 buffer (pH 7.5, 50°C, 400 rpm) and 0.5 mg/ml (dry cell weight) of whole cells of G. pallidus BTP-5x (as biocatalyst) resulted in an yield of 0.28 M of acetohydroxamic acid after 20 min reaction time at 50°C. The acetamide bioconversion rate was 90-95% (mol mol -1 ) and 51 g powder containing 40% (w/w) acetohydroxamic acid was recovered after lyophilization.

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The amidases from a Brevibacterium strain: Study and applications

Cited by 19 publications

References 123 publications

Identification and characterization of an aliphatic amidase in Helicobacter pylori

Identification and characterization of an aliphatic amidase in Helicobacter pylori

A Novel Amidase (Half-Amidase) for Half-Amide Hydrolysis Involved in the Bacterial Metabolism of Cyclic Imides

Biotransformation of Acetamide to Acetohydroxamic Acid at Bench Scale Using Acyl Transferase Activity of Amidase of Geobacillus pallidus BTP-5x MTCC 9225

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