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

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.

Download Full-text

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.

Download Full-text

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.

Download Full-text

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.

Download Full-text

Molecular Analysis of the Gene Encoding a Novel Chitin-Binding Protease from Alteromonas sp. Strain O-7 and Its Role in the Chitinolytic System

Journal of Bacteriology ◽

10.1128/jb.184.7.1865-1872.2002 ◽

2002 ◽

Vol 184 (7) ◽

pp. 1865-1872 ◽

Cited By ~ 18

Author(s):

Katsushiro Miyamoto ◽

Eiji Nukui ◽

Hiroyuki Itoh ◽

Takaji Sato ◽

Takeshi Kobayashi ◽

...

Keyword(s):

Molecular Mass ◽

Signal Sequence ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Chitinase Activity ◽

Maximum Activity ◽

Sequencing Analysis ◽

Gene Encoding ◽

Calculated Molecular Mass ◽

Chitin Binding Domain

ABSTRACT Alteromonas sp. strain O-7 secretes several proteins in response to chitin induction. We have found that one of these proteins, designated AprIV, is a novel chitin-binding protease involved in chitinolytic activity. The gene encoding AprIV (aprIV) was cloned in Escherichia coli. DNA sequencing analysis revealed that the open reading frame of aprIV encoded a protein of 547 amino acids with a calculated molecular mass of 57,104 Da. AprIV is a modular enzyme consisting of five domains: the signal sequence, the N-terminal proregion, the family A subtilase region, the polycystic kidney disease domain (PkdD), and the chitin-binding domain type 3 (ChtBD3). Expression plasmids coding for PkdD or both PkdD and ChtBD (PkdD-ChtBD) were constructed. The PkdD-ChtBD but not PkdD exhibited strong binding to α-chitin and β-chitin. Western and Northern analyses demonstrated that aprIV was induced in the presence of N-acetylglucosamine, N-acetylchitobiose, or chitin. Native AprIV was purified to homogeneity from Alteromonas sp. strain O-7 and characterized. The molecular mass of mature AprIV was estimated to be 44 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The optimum pH and temperature of AprIV were pH 11.5 and 35°C, respectively, and even at 10°C the enzyme showed 25% of the maximum activity. Pretreatment of native chitin with AprIV significantly promoted chitinase activity.

Download Full-text

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.

Download Full-text

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.

Download Full-text

Purification and partial characterization of a mitogenic protein released from preadipocytes of massively obese subjects

Biochemistry and Cell Biology ◽

10.1139/o90-110 ◽

1990 ◽

Vol 68 (4) ◽

pp. 764-768 ◽

Cited By ~ 2

Author(s):

Daniel A. K. Roncari ◽

Coral E. Thompson

Keyword(s):

Growth Factor ◽

Transforming Growth Factor ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Gel Filtration ◽

Radioreceptor Assay ◽

Massive Obesity ◽

Epidermal Growth ◽

Obese Subjects ◽

High Degree

A protein released into the culture medium by omental preadipocytes of massively obese persons, which stimulates the replication of rat perirenal preadipocytes, has been purified to a high degree. By gel filtration chromatography, the molecular mass of the mitogenic protein was ~66 000 daltons (Da), while on sodium dodecyl sulfate – polyacrylamide gel electrophoresis, two subunits were obtained, relative masses (Mr) of ~31 000 and ~35 000. The isoelectric point of the ~66 000 Da entity was 5.6 ± 0.2. By specific radioreceptor assay, the purified protein was related to epidermal growth factor and transforming growth factor alpha. It was not related to insulin-like growth factors I and II by radioimmunoassay and radioreceptor assay. We propose that the ~66 000 Mr protein, and other mitogenic proteins released by preadipocytes from massively obese persons, act through paracrine–autocrine mechanisms and may play a role in the development of the hyperplasia of enlarged fat cells characteristic of massive corpulence.Key words: preadipocyte, massive obesity, mitogenic, paracrine.

Download Full-text

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.

Download Full-text

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.

Download Full-text

Characterization of a Thermostable d-Stereospecific Alanine Amidase from Brevibacillus borstelensis BCS-1

Applied and Environmental Microbiology ◽

10.1128/aem.69.2.980-986.2003 ◽

2003 ◽

Vol 69 (2) ◽

pp. 980-986 ◽

Cited By ~ 22

Author(s):

Dae Heoun Baek ◽

Seok-Joon Kwon ◽

Seung-Pyo Hong ◽

Mi-Sun Kwak ◽

Mi-Hwa Lee ◽

...

Keyword(s):

Enzyme Activity ◽

Amino Acid ◽

Gel Electrophoresis ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Gel Filtration ◽

Optimum Temperature ◽

Gene Encoding ◽

Ph Range

ABSTRACT A gene encoding a new thermostable d-stereospecific alanine amidase from the thermophile Brevibacillus borstelensis BCS-1 was cloned and sequenced. The molecular mass of the purified enzyme was estimated to be 199 kDa after gel filtration chromatography and about 30 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that the enzyme could be composed of a hexamer with identical subunits. The purified enzyme exhibited strong amidase activity towards d-amino acid-containing aromatic, aliphatic, and branched amino acid amides yet exhibited no enzyme activity towards l-amino acid amides, d-amino acid-containing peptides, and NH2-terminally protected amino acid amides. The optimum temperature and pH for the enzyme activity were 85°C and 9.0, respectively. The enzyme remained stable within a broad pH range from 7.0 to 10.0. The enzyme was inhibited by dithiothreitol, 2-mercaptoethanol, and EDTA yet was strongly activated by Co2+ and Mn2+. The k cat/Km for d-alaninamide was measured as 544.4 ± 5.5 mM−1 min−1 at 50°C with 1 mM Co2+.

Download Full-text