Degradation of Chloroaromatics: Purification and Characterization of a Novel Type of Chlorocatechol 2,3-Dioxygenase of Pseudomonas putida GJ31

ABSTRACT A purification procedure for a new kind of extradiol dioxygenase, termed chlorocatechol 2,3-dioxygenase, that converts 3-chlorocatechol productively was developed. Structural and kinetic properties of the enzyme, which is part of the degradative pathway used for growth ofPseudomonas putida GJ31 with chlorobenzene, were investigated. The enzyme has a subunit molecular mass of 33.4 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Estimation of the native M r value under nondenaturating conditions by gel filtration gave a molecular mass of 135 ± 10 kDa, indicating a homotetrameric enzyme structure (4 × 33.4 kDa). The pI of the enzyme was estimated to be 7.1 ± 0.1. The N-terminal amino acid sequence (43 residues) of the enzyme was determined and exhibits 70 to 42% identity with other extradiol dioxygenases. Fe(II) seems to be a cofactor of the enzyme, as it is for other catechol 2,3-dioxygenases. In contrast to other extradiol dioxygenases, the enzyme exhibited great sensitivity to temperatures above 40°C. The reactivity of this enzyme toward various substituted catechols, especially 3-chlorocatechol, was different from that observed for other catechol 2,3-dioxygenases. Stoichiometric displacement of chloride occurred from 3-chlorocatechol, leading to the production of 2-hydroxymuconate.

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A metalloproteinase extracellularly released byCrithidia deanei

Canadian Journal of Microbiology ◽

10.1139/w03-081 ◽

2003 ◽

Vol 49 (10) ◽

pp. 625-632 ◽

Cited By ~ 15

Author(s):

Claudia Masini d'Avila-Levy ◽

Rodrigo F Souza ◽

Rosana C Gomes ◽

Alane B Vermelho ◽

Marta H Branquinha

Keyword(s):

Molecular Mass ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Gel Filtration ◽

Residual Activity ◽

Major Protein ◽

Motile Cells ◽

Sds Page ◽

Triton X

Actively motile cells from a cured strain of Crithidia deanei released proteins in phosphate buffer (pH 7.4). The molecular mass of the released polypeptides, which included some proteinases, ranged from 19 to 116 kDa. One of the major protein bands was purified to homogeneity by a combination of anion-exchange and gel filtration chromatographs. The apparent molecular mass of this protein was estimated to be 62 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDSPAGE). The incorporation of gelatin into SDSPAGE showed that the purified protein presented proteolytic activity in a position corresponding to a molecular mass of 60 kDa. The enzyme was optimally active at 37 °C and pH 6.0 and showed 25% of residual activity at 28 °C for 30 min. The proteinase was inhibited by 1,10-phenanthroline and EDTA, showing that it belonged to the metalloproteinase class. A polyclonal antibody to the leishmanial gp63 reacted strongly with the released C. deanei protease. After Triton X-114 extraction, an enzyme similar to the purified metalloproteinase was detected in aqueous and detergent-rich phases. The detection of an extracellular metalloproteinase produced by C. deanei and some other Crithidia species suggests a potential role of this released enzyme in substrate degradation that may be relevant to the survival of trypanosomatids in the host.Key words: endosymbiont, trypanosomatid, extracellular, proteinase.

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Carboxymethylhydroxymuconic semialdehyde dehydrogenase in the 4-hydroxyphenylacetate catabolic pathway of Pseudomonas putida

Biochemistry and Cell Biology ◽

10.1139/o86-169 ◽

1986 ◽

Vol 64 (12) ◽

pp. 1288-1293 ◽

Cited By ~ 6

Author(s):

Josefa M. Alonso ◽

Amando Garrido-Pertierra

Keyword(s):

Pseudomonas Putida ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Gel Filtration ◽

Competitive Inhibitor ◽

Catabolic Pathway ◽

Ph Optimum ◽

Semialdehyde Dehydrogenase ◽

Standard Assay ◽

Assay Conditions

5-Carboxymethyl-2-hydroxymuconic semialdehyde (CHMSA) dehydrogenase in the 4-hydroxyphenylacetate meta-cleavage pathway was purified from Pseudomonas putida by gel filtration, anion-exchange, and affinity chromatographies. Sodium dodecyl sulfate – polyacrylamide gel electrophoresis analysis suggested an approximate tetrameric molecular weight of 200 000. The purified enzyme showed a pH optimum at 7.8. The temperature–activity relationship for the enzyme from 27 to 45 °C showed broken Arrhenius plots with an inflexion at 36–37 °C. Under standard assay conditions, the enzyme acted preferentially with NAD. It could also catalyze the reduction with NADP (which had a higher Km), at 18% of the rate observed for NAD. The following kinetic parameters were found: Km(NAD) = 20.0 ± 3.6 μM, Km(CHMSA) = 8.5 ± 1.8 μM, and Kd(enzyme–NAD complex) = 7.8 ± 2.0 μM. The product NADH acted as a competitive inhibitor against NAD.

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Characterization of Biosynthetic Enzymes for Ectoine as a Compatible Solute in a Moderately Halophilic Eubacterium, Halomonas elongata

Journal of Bacteriology ◽

10.1128/jb.181.1.91-99.1999 ◽

1999 ◽

Vol 181 (1) ◽

pp. 91-99 ◽

Cited By ~ 111

Author(s):

Hisayo Ono ◽

Kazuhisa Sawada ◽

Nonpanga Khunajakr ◽

Tao Tao ◽

Mihoko Yamamoto ◽

...

Keyword(s):

Molecular Mass ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Gel Filtration ◽

Apparent Molecular Mass ◽

Optimum Temperature ◽

Sds Page ◽

Halomonas Elongata ◽

Optimum Ph

ABSTRACT 1,4,5,6-Tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (ectoine) is an excellent osmoprotectant. The biosynthetic pathway of ectoine from aspartic β-semialdehyde (ASA), in Halomonas elongata, was elucidated by purification and characterization of each enzyme involved. 2,4-Diaminobutyrate (DABA) aminotransferase catalyzed reversively the first step of the pathway, conversion of ASA to DABA by transamination with l-glutamate. This enzyme required pyridoxal 5′-phosphate and potassium ions for its activity and stability. The gel filtration estimated an apparent molecular mass of 260 kDa, whereas molecular mass measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was 44 kDa. This enzyme exhibited an optimum pH of 8.6 and an optimum temperature of 25°C and had Km s of 9.1 mM forl-glutamate and 4.5 mM for dl-ASA. DABA acetyltransferase catalyzed acetylation of DABA to γ-N-acetyl-α,γ-diaminobutyric acid (ADABA) with acetyl coenzyme A and exhibited an optimum pH of 8.2 and an optimum temperature of 20°C in the presence of 0.4 M NaCl. The molecular mass was 45 kDa by gel filtration. Ectoine synthase catalyzed circularization of ADABA to ectoine and exhibited an optimum pH of 8.5 to 9.0 and an optimum temperature of 15°C in the presence of 0.5 M NaCl. This enzyme had an apparent molecular mass of 19 kDa by SDS-PAGE and a Km of 8.4 mM in the presence of 0.77 M NaCl. DABA acetyltransferase and ectoine synthase were stabilized in the presence of NaCl (>2 M) and DABA (100 mM) at temperatures below 30°C.

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Studies on the subunits of human myeloperoxidase

Biochemical Journal ◽

10.1042/bj2220701 ◽

1984 ◽

Vol 222 (3) ◽

pp. 701-709 ◽

Cited By ~ 52

Author(s):

R L Olsen ◽

C Little

Keyword(s):

Heat Treatment ◽

Amino Acid ◽

Molecular Mass ◽

Amino Acid Composition ◽

Acid Composition ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Gel Filtration ◽

Additional Species ◽

Main Protein

The subunit composition of human myeloperoxidase was studied with the use of sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and gel filtration. The subunit pattern observed depended on the manner in which the enzyme was treated before analysis. Reduction before heat treatment in detergent led to two main protein species (Mr 57 000 and 10 500), whereas reduction during or after heat treatment yielded an additional species of Mr 39 000. Heating without any reductive pretreatment yielded the 39 000-Mr form as the major electrophoretic species. Carbohydrate staining showed large amounts of sugar on the 57 000-Mr species and little on the 10 500-Mr form. Significant amounts of haem were associated with this latter subunit. Haem also seemed to be associated with the 57 000-Mr form but not with the 39 000-Mr one. These three subunit forms were isolated and their amino acid composition analysed. The 57 000-Mr and 39 000-Mr forms had very similar amino acid composition and yielded an apparently identical collection of fragments on incubation with CNBr. Once separated, the subunits could not be interconverted. Generally, minor amounts of other molecular-mass forms were observed. The nature of the various molecular-mass forms originating from myeloperoxidase is discussed.

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Purification and Characterization of 1-Naphthol-2-Hydroxylase from Carbaryl-Degrading Pseudomonas Strain C4

Journal of Bacteriology ◽

10.1128/jb.01418-06 ◽

2007 ◽

Vol 189 (7) ◽

pp. 2660-2666 ◽

Cited By ~ 19

Author(s):

Vandana P. Swetha ◽

Aditya Basu ◽

Prashant S. Phale

Keyword(s):

Molecular Mass ◽

High Performance ◽

Polyacrylamide Gel Electrophoresis ◽

Substrate Inhibition ◽

Sodium Dodecyl ◽

Gel Filtration ◽

Sole Source ◽

Maximum Activity ◽

Ph Optimum ◽

Phenol Derivatives

ABSTRACT Pseudomonas sp. strain C4 metabolizes carbaryl (1-naphthyl-N-methylcarbamate) as the sole source of carbon and energy via 1-naphthol, 1,2-dihydroxynaphthalene, and gentisate. 1-Naphthol-2-hydroxylase (1-NH) was purified 9.1-fold to homogeneity from Pseudomonas sp. strain C4. Gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the enzyme is a homodimer with a native molecular mass of 130 kDa and a subunit molecular mass of 66 kDa. The enzyme was yellow, with absorption maxima at 274, 375, and 445 nm, indicating a flavoprotein. High-performance liquid chromatography analysis of the flavin moiety extracted from 1-NH suggested the presence of flavin adenine dinucleotide (FAD). Based on the spectral properties and the molar extinction coefficient, it was determined that the enzyme contained 1.07 mol of FAD per mol of enzyme. Although the enzyme accepts electrons from NADH, it showed maximum activity with NADPH and had a pH optimum of 8.0. The kinetic constants Km and V max for 1-naphthol and NADPH were determined to be 9.6 and 34.2 μM and 9.5 and 5.1 μmol min−1 mg−1, respectively. At a higher concentration of 1-naphthol, the enzyme showed less activity, indicating substrate inhibition. The Ki for 1-naphthol was determined to be 79.8 μM. The enzyme showed maximum activity with 1-naphthol compared to 4-chloro-1-naphthol (62%) and 5-amino-1-naphthol (54%). However, it failed to act on 2-naphthol, substituted naphthalenes, and phenol derivatives. The enzyme utilized one mole of oxygen per mole of NADPH. Thin-layer chromatographic analysis showed the conversion of 1-naphthol to 1,2-dihydroxynaphthalene under aerobic conditions, but under anaerobic conditions, the enzyme failed to hydroxylate 1-naphthol. These results suggest that 1-NH belongs to the FAD-containing external flavin mono-oxygenase group of the oxidoreductase class of proteins.

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Cloning and Characterization of 1-Deoxy-d-Xylulose 5-Phosphate Synthase fromStreptomyces sp. Strain CL190, Which Uses both the Mevalonate and Nonmevalonate Pathways for Isopentenyl Diphosphate Biosynthesis

Journal of Bacteriology ◽

10.1128/jb.182.4.891-897.2000 ◽

2000 ◽

Vol 182 (4) ◽

pp. 891-897 ◽

Cited By ~ 90

Author(s):

Tomohisa Kuzuyama ◽

Motoki Takagi ◽

Shunji Takahashi ◽

Haruo Seto

Keyword(s):

Molecular Mass ◽

Mevalonate Pathway ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Gel Filtration ◽

Initial Step ◽

Enzymatic Properties ◽

Isopentenyl Diphosphate ◽

Ph Optimum ◽

Nonmevalonate Pathway

ABSTRACT In addition to the ubiquitous mevalonate pathway,Streptomyces sp. strain CL190 utilizes the nonmevalonate pathway for isopentenyl diphosphate biosynthesis. The initial step of this nonmevalonate pathway is the formation of 1-deoxy-d-xylulose 5-phosphate (DXP) by condensation of pyruvate and glyceraldehyde 3-phosphate catalyzed by DXP synthase. The corresponding gene, dxs, was cloned from CL190 by using PCR with two oligonucleotide primers synthesized on the basis of two highly conserved regions among dxs homologs from six genera. Thedxs gene of CL190 encodes 631 amino acid residues with a predicted molecular mass of 68 kDa. The recombinant enzyme overexpressed in Escherichia coli was purified as a soluble protein and characterized. The molecular mass of the enzyme was estimated to be 70 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 130 kDa by gel filtration chromatography, suggesting that the enzyme is most likely to be a dimer. The enzyme showed a pH optimum of 9.0, with a V max of 370 U per mg of protein and Km s of 65 μM for pyruvate and 120 μM for d-glyceraldehyde 3-phosphate. The purified enzyme catalyzed the formation of 1-deoxyxylulose by condensation of pyruvate and glyceraldehyde as well, with aKm value of 35 mM ford-glyceraldehyde. To compare the enzymatic properties of CL190 and E. coli DXP synthases, the latter enzyme was also overexpressed and purified. Although these two enzymes had different origins, they showed the same enzymatic properties.

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Purification of a Necrosis-Inducing, Host-Specific Protein Toxin from Spore Germination Fluid of Alternaria panax

Phytopathology ◽

10.1094/phyto.2003.93.3.323 ◽

2003 ◽

Vol 93 (3) ◽

pp. 323-328 ◽

Cited By ~ 20

Author(s):

H. A. Quayyum ◽

M. Gijzen ◽

J. A. Traquair

Keyword(s):

Molecular Mass ◽

Spore Germination ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Gel Filtration ◽

American Ginseng ◽

Leaf Extracts ◽

Water Extracts ◽

Protein Toxin ◽

Alternaria Panax

Spore germination fluid of Alternaria panax, the causal agent of Alternaria blight of American ginseng (Panax quinquefolius), collected from water droplets or aqueous ginseng leaf extracts produced visible water-soaked lesions on wounded, detached leaflets after incubation for 48 h. Maximum development of brown, necrotic spots occurred 4 to 5 days after inoculation on attached and detached ginseng leaflets. Of 15 plant species tested, only American ginseng was susceptible to applications of spore inoculum or spore germination fluid. The phytotoxic activity of the spore germination fluid was destroyed by heat and treatment with proteinase A. The phytotoxic factor was retained by an ultrafiltration membrane with a 30-kDa molecular mass cut-off. Purification of the phytotoxic protein, named AP-toxin, was performed by anion exchange and gel filtration chromatography. Bioactive fractions eluted as a single peak. By comparison with protein standards, a molecular mass of 35 kDa was estimated for the native protein. The denatured protein toxin also had a mass of 35 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. Production of the protein toxin was induced on American ginseng leaflets and water extracts of ginseng leaves but not on leaves of other nonhost plants and their water extracts. The results show that A. panax produces a host-specific, proteinaceous toxin during colonization and pathogenesis of ginseng leaves.

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A bifunctional enzyme complex in coenzyme A biosynthesis: purification of pantetheine phosphate adenylyltransferase and dephospho-CoA kinase

Biochemical Journal ◽

10.1042/bj2150153 ◽

1983 ◽

Vol 215 (1) ◽

pp. 153-157 ◽

Cited By ~ 27

Author(s):

D M Worrall ◽

P K Tubbs

Keyword(s):

Gel Electrophoresis ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Gel Filtration ◽

Bifunctional Enzyme ◽

Enzyme Complex ◽

Major Band ◽

A Subunit ◽

Dimeric Protein ◽

Coenzyme A Biosynthesis

Pantetheine phosphate adenylyltransferase (EC 2.7.7.3) and dephospho-CoA kinase (EC 2.7.1.24) were purified to near homogeneity from pig liver. The purification steps included the use of Sepharose-linked triazine dyes and affinity elution by CoA. Both activities co-purified at every stage of the 18 000-fold purification. An Mr of 115 000 was obtained by gel filtration on Sephadex G-150, and the final preparation yielded one major band on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, with a subunit Mr of 57 000. It is concluded that pantetheine phosphate adenylyltransferase and dephospho-CoA kinase exist as a bifunctional dimeric protein, which could be designated CoA synthetase.

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Purification, Characterization, and Sequence Analysis of 2-Aminomuconic 6-Semialdehyde Dehydrogenase from Pseudomonas pseudoalcaligenes JS45

Journal of Bacteriology ◽

10.1128/jb.180.17.4591-4595.1998 ◽

1998 ◽

Vol 180 (17) ◽

pp. 4591-4595 ◽

Cited By ~ 26

Author(s):

Zhongqi He ◽

John K. Davis ◽

Jim C. Spain

Keyword(s):

Molecular Mass ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Gel Filtration ◽

Gene Encoding ◽

Multiple Sequence ◽

Pseudomonas Pseudoalcaligenes ◽

Semialdehyde Dehydrogenase ◽

Cell Extracts ◽

High Degree

ABSTRACT 2-Aminonumconic 6-semialdehyde is an unstable intermediate in the biodegradation of nitrobenzene and 2-aminophenol by Pseudomonas pseudoalcaligenes JS45. Previous work has shown that enzymes in cell extracts convert 2-aminophenol to 2-aminomuconate in the presence of NAD+. In the present work, 2-aminomuconic semialdehyde dehydrogenase was purified and characterized. The purified enzyme migrates as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with a molecular mass of 57 kDa. The molecular mass of the native enzyme was estimated to be 160 kDa by gel filtration chromatography. The optimal pH for the enzyme activity was 7.3. The enzyme is able to oxidize several aldehyde analogs, including 2-hydroxymuconic semialdehyde, hexaldehyde, and benzaldehyde. The gene encoding 2-aminomuconic semialdehyde dehydrogenase was identified by matching the deduced N-terminal amino acid sequence of the gene with the first 21 amino acids of the purified protein. Multiple sequence alignment of various semialdehyde dehydrogenase protein sequences indicates that 2-aminomuconic 6-semialdehyde dehydrogenase has a high degree of identity with 2-hydroxymuconic 6-semialdehyde dehydrogenases.

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Characterization of three kinetically distinct forms of glutamate decarboxylase from pig brain

Biochemical Journal ◽

10.1042/bj2310695 ◽

1985 ◽

Vol 231 (3) ◽

pp. 695-703 ◽

Cited By ~ 47

Author(s):

D C Spink ◽

T G Porter ◽

S J Wu ◽

D L Martin

Keyword(s):

Sodium Dodecyl Sulphate ◽

Glutamate Decarboxylase ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Kinetic Properties ◽

First Order ◽

Pig Brain ◽

A Subunit ◽

Activation Cycle

Pig brain contains three forms of glutamate decarboxylase with pI values of 5.3, 5.5 and 5.8, referred to as the α-, β- and γ-forms respectively. These forms were purified and kinetically characterized. The major synaptic form of glutamate decarboxylase (the β-form) migrated as a single band on electrophoresis in sodium dodecyl sulphate/polyacrylamide gels with an apparent Mr of 60 000. Sodium dodecyl sulphate/polyacrylamide gel electrophoresis followed by immunoblotting with an affinity-purified antibody to the enzyme indicated a subunit Mr of 60 000 for the α- and γ-forms as well. An extensive kinetic analysis, aided by an integrated equation that describes the inactivation and re-activation cycle of the enzyme, revealed that the three forms of the enzyme differ markedly in kinetic properties. The Km values for L-glutamate were 0.17, 0.45 and 1.24 mM respectively for the α-, β- and γ-forms. The Ki for 4-aminobutyrate, the first-order rate constants for inactivation by L-glutamate and 4-aminobutyrate, the rate constant for re-activation of the apoenzyme by pyridoxal 5′-phosphate and the dissociation constant for pyridoxal 5′-phosphate also differed in a similar way among the three forms; the values were in the order α-form less than β-form less than γ-form.

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