Purification and properties of chlorocatechol 1,2-dioxygenase from Alcaligenes denitrificans BRI 6011

1993 ◽  
Vol 39 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Carlos B. Miguez ◽  
Charles W. Greer ◽  
Jordan M. Ingram
Keyword(s):  
Gel Electrophoresis ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Apparent Molecular Weight ◽  
Logarithmic Growth Phase ◽  
Chlorobenzoic Acid ◽  
Alcaligenes Denitrificans ◽  
Purification And Properties ◽  
Chlorinated Catechols ◽  
Logarithmic Growth

The specific activity of chlorocatechol 1,2-dioxygenase from Alcaligenes denitrificans BRI 6011 was found to be maximal in the early logarithmic growth phase. The enzyme was purified from cultures at mid-log phase of growth using ammonium sulfate fractionation, and phenyl-Sepharose and DEAE-Sepharose chromatography. The protein gave a single band by SDS polyacrylamide gel electrophoresis with an apparent molecular weight of 33 000, and the temperature and pH optima were 30 °C and 7.5, respectively. Catechol, 3-chlorocatechol (3-CC), 4-CC, 3,4-dichlorocatechol (3,4-DCC), 3,5-DCC, 3,6-DCC, 3-methylcatechol (3-MC), and 4-MC served as substrates for the enzyme. The Vmax values for the dichlorocatechols were similar, while those for the monochlorinated and methylated catechols were higher. The Km values for all the chlorinated catechols were typically below 1 μM, while those for catechol and the methylated catechols were above 10 μM.Key words: chlorocatechol 1,2-dioxygenase, Alcaligenes denitrificans, purification, characterization, chlorobenzoic acid degradation.

Novel Catalatic Proteins of Bakers' Yeast. I. An Atypical Catalase

1973 ◽  
Vol 51 (11) ◽  
pp. 1551-1555 ◽  
Author(s):  
Tony C. M. Seah ◽  
A. R. Bhatti ◽  
J. G. Kaplan
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Native Protein ◽  
Wild Type ◽  
Major Band ◽  
Subunit Molecular Weight ◽  
Purification And Properties

At any stage of growth of a wild-type bakers' yeast, some 20% of the catalatic activity of crude extracts is not precipitable by means of antibody prepared against the typical catalase (catalase T), whose purification and properties have been previously described. Some of this catalatic activity is due to the presence of an atypical catalase (catalase A), a heme protein, with a molecular weight estimated as 170 000 – 190 000, considerably lower than that of the usual catalases (225 000 – 250 000). Preparations of catalase A were found to be homogeneous in the analytical ultracentrifuge and in polyacrylamide gel electrophoresis. Its subunit molecular weight, determined from its iron content, was 46 500, virtually the same as that of the major band obtained in gel electrophoresis in the presence of sodium dodecyl sulfate, suggesting that the native protein is tetrameric. Its specific activity is in the range of those reported for other typical catalases.

scholarly journals The purification and properties of the β-lactamase specified by the resistance factor R-1818 in Escherichia coli and Proteus mirabilis

1971 ◽  
Vol 123 (4) ◽  
pp. 493-500 ◽  
Author(s):  
J. W. Dale ◽  
J. T. Smith
Keyword(s):  
Escherichia Coli ◽  
Proteus Mirabilis ◽  
Gel Electrophoresis ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Resistance Factor ◽  
Ph Optimum ◽  
E Coli ◽  
R Factor ◽  
Purification And Properties

1. The β-lactamase specified by the R-1818 resistance factor in Escherichia coli was purified 300-fold; the resulting preparation gave a single peak on Sephadex G-100 and a single band on polyacrylamide-gel electrophoresis. 2. The β-lactamase specified by the same R-factor in Proteus mirabilis was purified over 2000-fold, but was still far from pure. The specific activity of this preparation was one-fifth that of the purified enzyme from E. coli. 3. The two enzymes were shown to be identical as regards substrate specificity, pH optimum, Km values and molecular weight. 4. It is suggested that the low β-lactamase activity of extracts of P. mirabilis (R-1818), about 5% of that from E. coli (R-1818) in crude extracts, could be due to inefficient transcription of the R-factor DNA by Proteus RNA polymerase.

scholarly journals Purification and properties of Cellvibrio gilvus cellobiose phosphorylase

1983 ◽  
Vol 209 (3) ◽  
pp. 803-807 ◽  
Author(s):  
T Sasaki ◽  
T Tanaka ◽  
S Nakagawa ◽  
K Kainuma
Keyword(s):  
Gel Electrophoresis ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Competitive Inhibitor ◽  
Polyacrylamide Gel ◽  
Protamine Sulphate ◽  
Purification And Properties ◽  
Cellobiose Phosphorylase ◽  
Optimum Ph

The cellobiose phosphorylase (EC 2.4.1.20) of Cellvibrio gilvus, which is an endocellular enzyme, has been purified 196-fold with a recovery of 11% and a specific activity of 27.4 mumol of glucose 1-phosphate formed/min per mg of protein. The purification procedure includes fractionation with protamine sulphate, and hydroxyapatite and DEAE-Sephadex A-50 chromatography. The enzyme appears homogeneous on polyacrylamide-gel electrophoresis, and a molecular weight of 280 000 was determined by molecular-sieve chromatography. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis revealed a single band and mol.wt. 72 000, indicating that cellobiose phosphorylase consists of four subunits. The enzyme had a specificity for cellobiose, requiring Pi and Mg2+ for phosphorylation, but not for cellodextrin, gentibiose, laminaribiose, lactose, maltose, kojibiose and sucrose. The enzyme showed low thermostability, an optimum pH of 7.6 and a high stability in the presence of 2-mercaptoethanol or dithiothreitol. The Km values for cellobiose and Pi were 1.25 mM and 0.77 mM respectively. Nojirimycin acted as a powerful pure competitive inhibitor (with respect to cellobiose) of the enzyme (Ki = 45 microM). Addition of thiol-blocking agents to the enzyme caused 56% inhibition at 500 microM-N-ethylmaleimide and 100% at 20 microM-p-chloromercuribenzoate.

Low Molecular Weight Trypsin-Plasmin Inhibitors Isolated from Papain Treated Urinary Trypsin Inhibitor

1982 ◽  
Vol 47 (01) ◽  
pp. 014-018 ◽  
Author(s):  
H Sumi ◽  
N Toki ◽  
S Takasugi ◽  
S Maehara ◽  
M Maruyama ◽  
...  
Keyword(s):  
Trypsin Inhibitor ◽  
Gel Electrophoresis ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Chromatography ◽  
Urinary Trypsin Inhibitor ◽  
Plasmin Activity ◽  
Molecular Weights ◽  
Plasmin Inhibitors

SummaryPapain treatment of human urinary trypsin inhibitor (UTI67; mol. wt. 43,000 by SDS-polyacrylamide gel electrophoresis, specific activity 1,897 U/mg protein) produced four new protease inhibitors, which were highly purified by gel chromatography on Sephadex G-100 and isoelectric focusing. The purified inhibitors (UTI26, UTI9-I, UTI9-II, and UTI9-III) were shown to be homogeneous by polyacrylamide disc gel electrophoresis, and had apparent molecular weights of 26,000, 9,000, 9,000, and 9,800, respectively, by sodium dodecyl sulfate gel electrophoresis. During enzymatic degradation of UTI67, the amino acid compositions changed to more basic, and the isoelectric point increased from pH 2.0 (UTI67) to pHs 4.4, 5.2, 6.6, and 8.3 (UTI26, UTI9-I, UTI9-II, and UTI9-III), respectively. Both the parent and degraded inhibitors had anti-plasmin activity as well as antitrypsin and anti-chymotrypsin activities. Much higher anti-plasmin/anti-trypsin and anti-plasmin/anti-chymotrypsin activities were observed in the degraded inhibitors than in the parent UTI67. They competitively inhibited human plasmin with Ki values of 1.13 X 10-7 - 2.12 X 10-6 M (H-D-Val-Leu-Lys-pNA substrate). The reactions were very fast and the active site of the inhibitors to plasmin was thought to be different from that to trypsin or chymotrypsin.

Monoclonal antibodies against surface antigens of schistosomula of Schistosoma mansoni

Parasitology ◽  
1982 ◽  
Vol 84 (1) ◽  
pp. 65-82 ◽  
Author(s):  
D. W. Taylor ◽  
A. F. Butterworth
Keyword(s):  
Monoclonal Antibodies ◽  
Gel Electrophoresis ◽  
Primary Infection ◽  
Polyacrylamide Gel Electrophoresis ◽  
Apparent Molecular Weight ◽  
Surface Antigens ◽  
Soft Agar ◽  
Surface Proteins ◽  
Spleen Cells

SUMMARYMonoclonal antibodies have been produced after fusion of NS-1 murine myeloma cells with spleen cells from mice immunized either by chronic primary infection or with irradiated cercariae: in both cases, animals were challenged with live cercariae 7 days before fusion. The initial cultures were screened for anti-schistosomular antibodies both by a radioimmunoassay with whole schistosomulum extracts and by immunofluorescence. There was no correlation between the two techniques and subsequent screening was carried out by immunofluorescence. Cloning was carried out in soft agar and 7 cloned cell lines, from 5 initial cultures, were selected for detailed study. Products of 6 of these 7 lines were monoclonal, as judged by isoelectricfocusing of [35S]methionine-labelled supernatant fluids, and their binding to live schistosomula was specific. None of the antibodies showed detectable activity in mediating eosinophil- or complement-dependent damage to schistosomula in vitro. However, 2 antibodies were successfully used to isolate surface proteins with an apparent molecular weight of 24000 on SDS-polyacrylamide gel electrophoresis.

scholarly journals Structural properties of homogeneous protein disulphide-isomerase from bovine liver purified by a rapid high-yielding procedure

1983 ◽  
Vol 213 (1) ◽  
pp. 225-234 ◽  
Author(s):  
N Lambert ◽  
R B Freedman
Keyword(s):  
Amino Acid ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Sedimentation Coefficient ◽  
Bovine Liver ◽  
Polyacrylamide Gel ◽  
Protein Disulphide Isomerase

Protein disulphide-isomerase from bovine liver was purified to homogeneity as judged by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, two-dimensional electrophoresis and N-terminal amino acid analysis. The preparative procedure, a modification of that of Carmichael, Morin & Dixon [(1977) J. Biol. Chem. 252, 7163-7167], is much faster and higher-yielding than previous procedures, and the final purified material is of higher specific activity. The enzyme has Mr 57 000 as determined by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, both in the presence and in the absence of thiol compounds. Gel-filtration studies on Sephadex G-200 indicate an Mr of 107 000, suggesting that the native enzyme is a homodimer with no interchain disulphide bonds. Ultracentrifugation studies give a sedimentation coefficient of 3.5S, implying that the enzyme sediments as the monomer. The isoelectric point, in the presence of 8 M-urea, is 4.2, and some microheterogeneity is detectable. The amino acid composition is comparable with previous analyses of this enzyme from bovine liver and of other preparations of thiol:protein disulphide oxidoreductases whose relation to protein disulphide-isomerase has been controversial. The enzyme contains a very high proportion of Glx + Asx residues (27%). The N-terminal residue is His. The pure enzyme has a very small carbohydrate content, determined as 0.5-1.0% by the phenol/H2SO4 assay. Unless specific steps are taken to remove it, the purified enzyme contains a small amount (5 mol/mol of enzyme) of Triton X-100 carried through the purification.

scholarly journals Purification and properties of β-N-acetylhexosaminidase from the mollusc Helicella ericetorum Müller

1978 ◽  
Vol 175 (2) ◽  
pp. 743-750 ◽  
Author(s):  
P Calvo ◽  
A Reglero ◽  
J A Cabezas
Keyword(s):  
Active Site ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Mixed Substrates ◽  
Ph Optimum ◽  
Terrestrial Mollusc ◽  
Buffer Solutions ◽  
Purification And Properties ◽  
Competitive Inhibitors ◽  
Ph Range

1. A beta-N-acetylhexosaminidase was purified 330-fold from the digestive gland of the terrestrial mollusc Helicella ericetorum Müller. 2. Its pH optimum is 4.5 for both beta-N-acetylglucosaminidase and beta-N-acetylgalactosaminidase activities in two buffer solutions; it is fully stable at 37 degrees C for 2h in the pH range 3.8–4.6 and shows one isoelectric point (pH 4.83). 3. The estimated mol.wt. is between 120,000 and 145,000. 4. The enzyme shows an endo-beta-N-acetylhexosaminidase activity on natural substrates such as ovalbumin, ovomucoid, chondroitin 4-sulphate, chitin and hyaluronic acid. 5. Two forms of the enzyme were separated by preparative polyacrylamide-gel electrophoresis. 6. Km and Vmax. for p-nitrophenyl 2-acetamido-2-deoxy-beta-D-glucopyranoside and p-nitrophenyl 2-acetamide-2-deoxy-beta-D-galactopyranoside are 0.43 mM, 30.1 micronmol of p-nitrophenol/min per mg and 0.19 mM, 8.6 micronmol of p-nitrophenol/min per mg respectively. 7. It is inhibited by Hg2+, Fe3+, acetate, some lactones, N-acetylgalactosamine, N-acetylglucosamine and mannose. 8. Mixed-substrates analysis and Ki values for competitive inhibitors indicated that beta-N-acetylglucosaminidase and beta-N-acetylgalactosaminidase activities are catalysed by the enzyme at the same active site.

scholarly journals Purification and properties of 6-phosphogluconate dehydrogenase from sheep liver

1969 ◽  
Vol 115 (4) ◽  
pp. 639-643 ◽  
Author(s):  
R. H. Villet ◽  
K. Dalziel
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sedimentation Velocity ◽  
Sedimentation Equilibrium ◽  
Equilibrium Studies ◽  
Phosphogluconate Dehydrogenase ◽  
Sheep Liver ◽  
Equilibrium Sedimentation ◽  
Purification And Properties

A method is described for the isolation of 6-phosphogluconate dehydrogenase from sheep liver. The product appears to be homogeneous in polyacrylamide-gel electrophoresis and in sedimentation-velocity and sedimentation-equilibrium studies in the ultracentrifuge. The molecular weight is estimated as 129000 from equilibrium sedimentation.

Purification and properties of mercuric reductase from Yersinia enterocolitica 138A14

1993 ◽  
Vol 39 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Mohamed Blaghen ◽  
Dominique J. M. Vidon ◽  
Mohamed Said El Kebbaj
Keyword(s):  
Molecular Weight ◽  
Yersinia Enterocolitica ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Mercury Resistance ◽  
Thiol Compounds ◽  
Mercuric Reductase ◽  
Purification And Properties ◽  
Layer Chromatography

A mercuric ion-reducing flavoprotein was purified from Yersinia enterocolitica 138A14 using dye matrix affinity chromatography. The purified enzyme had a characteristic absorption spectrum similar to those of flavin compounds, and FAD was detected as a part of the purified enzyme by thin-layer chromatography. Freshly purified preparations of the enzyme showed a single band on SDS polyacrylamide gel electrophoresis with a molecular weight of 70 000. The isolated enzyme had a molecular weight of about 200 000 as determined by gel filtration and disc gel electrophoresis. These results suggest an apparently trimeric structure of the enzyme. Dithiothreitol treatment disrupted the trimer into a dimeric structure of 140 000. Along with ageing, as well as limited proteolytic digestion, the enzyme evolved to give a dimeric molecule of 105 000 composed of two identical subunits of 52 000. The combination of the purified enzyme with HgCl2, or unexpectedly with merthiolate, oxidised the NADPH, which was followed spectrophotometrically. The Km for HgCl2 was dependent on the concentration of exogenous thiol compounds. A comparison of physical properties as well as kinetic characteristics indicated that the enzyme from Y. enterocolitica 138A14 is similar to mercuric reductases isolated from other mercury-resistant bacteria.Key words: Yersinia enterocolitica, mercury resistance, mercuric reductase.

Variation in goat fibre protein

1989 ◽  
Vol 40 (3) ◽  
pp. 675 ◽  
Author(s):  
DJ Tucker ◽  
AHF Hudson ◽  
A Laudani ◽  
RC Marshall ◽  
DE Rivett
Keyword(s):  
Molecular Weight ◽  
Sodium Dodecyl Sulfate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Apparent Molecular Weight ◽  
Wool Fibre ◽  
Two Dimensional ◽  
Protein Patterns ◽  
Cashmere Goats

The proteins from a range of cashmere, mohair, angoratcashmere crossbred and wool fibre samples were extracted at pH 8 with 8 M urea containing dithiothreitol, and were then radiolabelled by S-carboxymethylation using iodo(2-14C) acetate. The proteins from each sample were examined by two dimensional polyacrylamide gel electrophoresis in which the separation in the first dimension was according to charge at pH 8.9 and in the second dimension according to apparent molecular weight in the presence of sodium dodecyl sulfate. After electrophoresis the proteins were detected by fluorography. Protein differences in keratin samples from some individual goats existed, although the overall protein patterns were similar. None of the differences were consistent with any one goat fibre type. The protein patterns obtained for fibre samples from individual cashmere goats showed some differences when compared to those found for commercial blends from the same country of origin, indicating that blending can mask any animal-to-animal variation. While the electrophoretic technique does not unequivocally distinguish between cashmere, mohair and angora/cashmere crossbred fibres it does differentiate between wool and goat fibres.

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