Phosphodiesterase-phosphomonoesterases from Fusarium moniliforme. VI. A modified method of purification and identification of isozymes.

Fusarium phosphodiesterase-phosphomonesterase was purified 1,630-fold with 19% yield from dried powder of the culture medium by a modified method consisting of seven steps. The purified preparation was shown to be devoid of inactive protein by disc electrophoresis. The preparation was homogeneous with respect to size as demonstrated by gel filtration, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and ultracentrifugation. The molecular weights determined by gel filtration on Sephadex G-200 and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis were 106,000 and 100,000, respectively. The sedimentation coefficient at infinite dilution was 5.71 S. Isoelectric focusing of the purified preparation showed the presence of at least four isozymes with isoelectric points of 6.6, 6.3, 6.2, and 5.9.     

Antioxidant Properties of the Peptides Isolated From Ganoderma lucidum Fruiting Body

Ganoderma lucidum is widely used as traditional medicine for centuries particularly in China, Japan and Korea. Many bioactive metabolites isolated from G. lucidum were therapeutically active against various diseases. The peptide isolated from water extract of G. lucidum was purified by employing Sephadex G-25, Sephadex G-50 and reverse phase HPLC column chromatography. The antioxidant property of the peptide fractions was determined by various in vitro methods. All fractions obtained from Sephadex G-25 and fraction G from Sephadex G-50 are effective antioxidants and comparably fraction C has the highest antioxidant activity. The molecular weight of purified peptide determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, gel filtration chromatography and Matrix-assisted laser desorption ionization time-of-flight-mass spectrometer was found to be 2.8, 3.34 and 3.35?kDa respectively. The amino acid composition of the peptide was rich in phenylalanine, aspartic acid, proline, histidine and isoleucine. Peptide isolated in the present investigation suggests that has beneficial antioxidant properties may be due to its low molecular weight and specific amino acid composition.     

Highly acidic proteins from human brain: purification and properties of Glu-50 protein

Three extremely acidic proteins were isolated from human brain and purified to apparent homogeneity. One of them, Glu-50 protein, contained much glutamic acid (about 50% of the total amino acids). Its purification involved ammonium sulfate fractionation, DEAE-Sephadex A-50 chromatography, and gel filtration on Sephadex G-100 and G-75. Its molecular weight was determined to be 11,000 by SDS polyacrylamide gel electrophoresis and 34,000-36,000 by gel filtration on Sephadex G-75, suggesting that it consists of three identical polypeptide chains. Its isoelectric point was pH 3.9. Its N-terminal amino acid sequence was NH2-Asp-Glu-Pro-Pro-Asp-Glu and its C-terminal amino acid was Lys. It contained no detectable carbohydrate.     

Identification and purification of a new staphylococcal enterotoxin, H.

A staphylococcal enterotoxin which elicited an emetic response in monkeys but did not share antigenic determinants with any of the identified enterotoxins was identified and purified from Staphylococcus aureus FRI-569. The emetic activity of this new enterotoxin was neutralized only by antibodies specific to it and not by antibodies to enterotoxins A, B, C, D, and E or toxic shock syndrome toxin 1. Immunodiffusion assays did not detect cross-reactivity between this new and all the other identified enterotoxins. The purification procedure involved removal of the enterotoxin from culture supernatant fluids by batch adsorption with CG-50 resin, CM-Sepharose FL ion-exchange chromatography, and Sephacryl 100 HR and Bio-Gel P-30 gel filtration. The molecular weight of this enterotoxin, 27,300, determined by gel filtration on Sephacryl 100 HR agreed with the molecular weight, 28,500, determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The apparent migration of this enterotoxin determined by SDS-PAGE did not shift in the presence of a disulfide reducing agent, indicating that it is composed of a single-chain protein. The N-terminal amino acid sequence of the enterotoxin was determined to be Glu-Asp-Leu-His-Asp-Lys-Ser-Glu-Leu-Thr-Asp-Leu-Ala-Leu-Ala-Asn-Ala-Tyr- Gly- Gln-Tyr-Asn-His-Pro-Phe-Ile-Lys-Glu-Asn-Ile, which did not match the N-terminal sequences of any known proteins. The isoelectric point of the enterotoxin determined by isoelectric focusing was about 5.7.(ABSTRACT TRUNCATED AT 250 WORDS)     

Purification and subunit structure of recBC DNase from Escherichia coli harboring a recB and recC genes-inserted plasmid

recBC DNase of Escherichia coli has been purified from the transformant, HB101/pFS11-04 (recB+ recC+), by successive ammonium sulfate fractionation, DEAE-cellulose chromatography, Sephadex G-150 gel filtration, hydroxyapatite chromatography, DNA cellulose affinity chromatography, and second DEAE-cellulose chromatography. The purified enzyme was obtained in an overall yield of 3%. The enzyme protein appeared as a single pure component on native polyacrylamide gel electrophoresis. The purified enzyme was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and two-dimensional electrophoresis. The results show that recBC DNase consists of two nonidentical subunits with molecular weights of 125,000 and 135,000, and isoelectric points of 5.6 and 5.7, respectively.     

Purification and properties of a second enzyme catalyzing the splitting of carbon-mercury linkages from mercury-resistant Pseudomonas K-62.

An enzyme (splitting enzyme 2) which catalyzes the splitting of carbon-mercury linkage of arylmercury compounds was found in extracts of mercury-resistant Pseudomonas K-62. This enzyme was purified about 725-fold by treatment with streptomycin, precipitation with ammonium sulfate, and successive chromatography on Sephadex G-75 and diethylaminoethyl-cellulose. A purified preparation of the enzyme showed a single band in electrophoresis either on polyacrylamide or sodium dodecyl sulfate-containing polyacrylamide gels. The molecular weight of the enzyme was estimated to be 20,000 (determined by Sephadex G-75 gel filtration) 17,000 (determined by sodium dodecyl sulfate-polyacrylamide disc gel electrophoresis). The enzyme showed a Km of 180 micron and a Vmax of 3.1 mumol/min per mg for p-chloromercuribenzoic acid and a Km of 250 micron and a Vmax of 20 mumol/min per mg for phenylmercuric acetate. The optimum temperature and pH for the reaction were 40 degrees C and 5.0, respectively.     

Theta-toxin of Clostridium perfringens. I. Purification and some properties.

Theta-Toxin, an oxygen-labile hemolysin produced by Clostridium perfringens, was purified 3300 fold from culture filtrate by successive chromatography on DEAE-Sephadex A-50 and Sephadex G-150. The purified toxin gave two distinct bands in disc electrophoresis, while the same material, after mild reduction with dithiothreitol, yielded a single band, indicating that the purified theta-toxin contained, as well as a reduced, active form, an oxidized, inactive form of toxin. These two forms of the toxin had a similar, if not identical molecular size. The purified preparation gave a single band in a sodium dodecyl sulfate polyacrylamide gel electrophoresis and formed a single precipitin line with National Standard gas gangrene (C. perfringens) antitoxin. By sodium dodecyl sulfate polyacrylamide gel electrophoresis, the molecular weight of theta-toxin was estimated to be 51 000, the value being in exact accordance with that obtained by amino acid analysis. The amino acid composition of theta-toxin was very close to that of cereolysin, an oxygen-labile hemolysin produced by Bacillus cereus. The amino-terminal residue of theta-toxin was lysine as determined by the Dansyl method.     

Purification and characterization of alpha-toxin of Clostridium oedematiens type A

The alpha-toxin of Clostridium oedematiens type A was purified from culture filtrate by two steps of column chromatography and repeated gel filtration. The purified alpha-toxin proved homogeneous in polyacrylamide gel electrophoresis and agar gel double diffusion. The molecular weight of the alpha-toxin was estimated at 280,000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis and at 260,000 by gel filtration on a Sephadex G-200 column. The isoelectric point determined by isoelectric focusing polyacrylamide gel electrophoresis was 6.1. No dissociation of the purified alpha-toxin into subunits was demonstrated in sodium dodecyl sulfate polyacrylamide gel electrophoresis. The 50% lethal and edematizing doses per mg protein of the purified alpha-toxin were 5.9 X 10(4) and 5.9 X 10(5), respectively. The L +/50 doses per mg protein of the toxin was 4.6 X 10(3). The purified alpha-toxin, when injected intradermally into the rabbit skin, induced increased vascular permeability. The toxin contained little or no hemolytic or lecithinase activity. These results attest that the lethal, edematizing and vascular permeability-enhancing activities elicited by C. oedematiens type A culture reside on the same protein molecule.     

Purification of N-hydroxy-2-acetylaminofluorene reductase from rabbit liver cytosol

N-Hydroxy-2-acetylaminofluorene reductase was purified from rabbit liver cytosol by fractionation with ammonium sulfate, and chromatography with DEAE-cellulose, Sephadex G-200 and hydroxylapatite. The purified enzyme was homogeneous by the criterion of sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The molecular weight of the enzyme was estimated to be 34,000 by the electrophoresis and by gel filtration on Sephadex G-200. The enzyme required cysteine, glutathione, dithiothreitol, 2-mercaptoethanol, NADPH or NADH as an electron donor. The enzyme activity was inhibited by p-chloromercuribenzoic acid, N-ethylmaleimide, cupric sulfate or disulfiram, but little by oxygen.     

Purification and characterization of an abscisic acid-inducible anionic peroxidase associated with suberization in potato (Solanum tuberosum)

An anionic peroxidase (EC 1.11.1.7), thought to be involved in suberization, was purified 110-fold from wound-healing slices of Solanum tuberosum by a combination of ammonium sulfate fractionation, Sephadex G-100 gel filtration, isoelectric focusing, and phenyl-Sepharose CL-4B chromatography in 24% yield. The purified enzyme was homogeneous as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and horizontal thin-layer polyacrylamide gel electrophoresis. The molecular weight of the enzyme was estimated to be 47,000 by both Sephadex G-100 gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This peroxidase was found to be a glycoprotein containing about 17% carbohydrate, approximately one-quarter of which was shown to be glucosamine residues. It was found to have an isoelectric point of 3.15. An anionic peroxidase was also isolated from abscisic acid-treated callus tissue culture of S. tuberosum by the above purification procedure. The two enzymes were shown to be immunologically similar, if not identical, based on their cross-reactivity with rabbit antibody prepared against the peroxidase from wound-healing slices, whereas the major cationic peroxidase from wound-healing slices did not cross-react with this antibody. The anionic enzyme from both sources showed very similar specific activities when assayed with a range of substrates, whereas the specific activities found for the cationic isozyme isolated from wound-healing slices were quite different.     

Purification and Properties of Clostridium botulinum Type F Toxin

Clostridium botulinum type F toxin of proteolytic Langeland strain was purified. Toxin in whole cultures was precipitated with (NH₄)₂SO₄. Extract of the precipitate was successively chromatographed on diethylaminoethyl-cellulose at pH 6.0, O-(carboxymethyl) cellulose at pH 4.9, Sephadex G-200 at pH 8.1, quaternary aminoethyl-Sephadex at pH 4.9, and finally diethylaminoethyl-cellulose at pH 8.1. The procedure recovered 14% of the toxin assayed in the starting culture. The toxin was homogeneous by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, double gel diffusion serology, and isoelectric focusing. Purified toxin had a molecular weight of 150,000 by gel filtration and 155,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Specific toxicity was 9.6 × 10⁶ mean lethal doses per absorbancy (278 nm) unit. Sub-units of 105,000 and 56,000 molecular weight are found when purified toxin is treated with a disulfide reducing agent and electrophoresed on sodium dodecyl sulfate-polyacrylamide gels. Reciprocal cross neutralizations were demonstrated when purified type F and E toxins were reacted with antitoxins which were obtained with immunizing toxoids prepared with purified toxins.     

Purification of (Ca2+-Mg2+)-ATPase from rat liver plasma membranes

The Ca2+-stimulated, Mg2+-dependent ATPase from rat liver plasma membranes was solubilized using the detergent polyoxyethylene 9 lauryl ether and purified by column chromatography using Polybuffer Exchanger 94, concanavalin A-Sepharose 4B, and Sephadex G-200. The molecular weight of the enzyme, estimated by gel filtration in the presence of the detergent on a Sephadex G-200 column, was 200,000 +/- 15,000. The enzyme was purified at least 300-fold from rat liver plasma membranes and had a specific activity of 19.7 mumol/mg/min. Polyacrylamide gel electrophoresis under nondenaturing conditions of the purified enzyme indicated that the enzymatic activity correlated with the major protein band. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis, one major band in the molecular weight range of 70,000 +/- 5,000 was seen. The isoelectric point of the purified enzyme was 6.9 +/- 0.2 as determined by analytical isoelectric focusing. The enzyme was activated by Ca2+ with an apparent half-saturation constant of 87 +/- 2 nM for Ca2+. Calmodulin and trifluoperazine at the concentration of 1 microgram/ml and 100 microM, respectively, had no effect on the enzymatic activity.     

Purification and initial characterization of guinea pig testicular acrosin

Guinea pig (GP) acrosin was purified following acid extraction of testicular acetone powder, pH precipitation of the soluble extract, gel filtration on Sephadex G-100, ion-exchange chromatography on SP-Sephadex, and affinity chromatography on Concanavalin A-Sepharose. Final purification was achieved by re-chromatography on Sephadex G-100. Enzymatic activity was detected by following the hydrolysis of N-benzyloxycarbonylarginyl amide of 7-amino-4-trifluoromethylcoumarin at 37 degrees C, pH 8.0, before and after activation. GP testicular acrosin exhibited a molecular weight of 48,000 by gel filtration and 34,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Following SDS-PAGE in gels containing 0.1% gelatin, protease activity was observed to comigrate with the major protein detected by silver staining. The purified GP acrosin showed cross-reactivity with a monospecific polyclonal rabbit antiserum directed against boar sperm acrosin and exhibited reversible pH-dependent activation. The physiochemical characteristics of the purified protein, including the amino acid composition, resemble those reported for acrosins from other species.     

Uroporphyrinogen decarboxylase. Purification, properties, and inhibition by polychlorinated biphenyl isomers

Uroporphyrinogen decarboxylase (EC 4.1.1.37) which converts uroporphyrinogen I or III into coproporphyrinogen I or III, respectively, was purified about 5,500-fold from chicken erythrocytes. Purification was accomplished by chromatography on DEAE-cellulose, ammonium sulfate fractionation, chromatography on Sephadex G-100, and chromatofocusing. The most purified preparation was homogeneous on polyacrylamide gel electrophoresis and had a specific activity of 1,420 units/mg of protein, the highest value so far reported. The molecular weight, as determined by Sephadex G-150 gel chromatography, is 79,000. The subunit molecular weight, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, is 39,700, suggesting that uroporphyrinogen decarboxylase is dimeric in form. The purified enzyme had an isoelectric point of 6.2 and a pH optimum of 6.8. The SH reagents inhibited the enzyme activity, but neither metal ions nor cofactor requirements could be demonstrated. A new and simple method for the separation of free uroporphyrin, hepta-, hexa-, and pentacarboxylic porphyrins and coproporphyrin was developed using a high pressure liquid chromatograph equipped with a spectrofluorometric detector. Kinetic studies of the sequential decarboxylation of uroporphyrinogen with purified enzyme were performed. 3,4,3',4'-Tetrachlorobiphenyl and 3,4,5,3',4'5'-hexachlorobiphenyl which specifically induce delta-aminolevulinic acid synthetase also strongly inhibit uroporphyrinogen decarboxylase directly at two steps, i.e. first in the formation of hexacarboxylic porphyrinogen III from heptacarboxylic porphyrinogen III and second in the formation of heptacarboxylic porphyrinogen III from uroporphyrinogen III.     

Purification and some properties of the glycolipid transfer protein from pig brain

A glycolipid-specific lipid transfer protein has been purified to apparent homogeneity from pig brain post-mitochondrial supernatant. The purified protein was obtained after about 6,000-fold purification at a yield of 19%. Evidence for the homogeneity of the purified protein includes the following: (i) a single band in acidic gel electrophoresis, in sodium dodecyl sulfate-gel electrophoresis, (ii) a single band in analytical gel isoelectric focusing, (iii) exact correspondence between the glycolipid transfer activity and stained protein absorbance in the acidic gel electrophoresis, and (iv) coincidence between the transfer activity and protein absorption at 280 nm in gel filtration through Ultrogel AcA 54. The protein has an isoelectric point of about 8.3 and a molecular weight of 22,000, as measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A molecular weight of 15,000 was calculated from AcA 54 gel filtration. The amino acid composition has been determined. The protein binds [3H]galactosylceramide but not [3H]phosphatidylcholine. Under the conditions used, 1 mol of the transfer protein bound about 0.13 mol of [3H]galactosylceramide. The glycolipid transfer protein-[3H]galactosylceramide complex was isolated by a Sephadex G-75 chromatography. An incubation of the complex with liposomes resulted in the transfer of [3H]galactosylceramide from the complex to the acceptor liposomes. The result indicates that the complex functions as an intermediate in the glycolipid transfer reaction. The protein facilitates the transfer of [3H]galactosylceramide from donor liposomes to acceptor liposomes lacking in glycolipid as well as to acceptor liposomes containing galactosylceramide.     

Prolidase from bovine intestine: purification and characterization

Prolidase [iminodipeptidase, EC 3.4.13.9] was highly purified from the cytosol fraction of bovine small intestine by a series of column chromatographies on DEAE-Toyopearl, Sephadex G-150, PCMB-T-Sepharose and hydroxyapatite. The purified enzyme appeared homogeneous as judged by disc gel electrophoresis. The enzyme was most active at pH 7.2 with Gly-Pro as substrate. It was stable between pH 5.5 and 8.5 for 30 min at 30 degrees C and retained half of the activity after 15 min at 40 degrees C. It was completely inactivated by p-chloromercuribenzoate (PCMB) but not inhibited by diisopropylphosphorofluoridate (DFP), phenylmethane sulfonylfluoride (PMSF) and metal chelators. Its amino acid composition was determined. Its molecular weight was estimated to be 116,000 by gel filtration on Sephadex G-150 and 56,000 by sodium dodecyl sulfate (SDS) gel electrophoresis, suggesting that it is a dimer. It hydrolyzed dipeptides represented as X-Pro (X = amino acid).     

Purification and characterization of peptidylarginine deiminase from rabbit skeletal muscle

The preceding paper described the identification and some properties of peptidylarginine deiminase, which catalyzes the deimination of arginyl residues in protein, from rabbit skeletal muscle, kidney, brain, and lung. In the present work we purified peptidylarginine deiminase from rabbit skeletal muscle with a 16% yield by 7 steps. The purification involved ion-exchange chromatography on DEAE-Sephacel, gel filtration on Bio-Gel A-0.5 m, and affinity chromatography on soybean trypsin inhibitor-Sepharose 4B and aminohexyl-Sepharose 4B. The purified enzyme was homogeneous on polyacrylamide gel electrophoresis with and without sodium dodecyl sulfate. The molecular weight of the enzyme was estimated to be about 83,000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis and 130,000-140,000 by gel filtration on Sephadex G-200. The isoelectric point was 5.3 and the amino acid composition was also determined. The enzyme preferably catalyzed the formation of citrulline derivatives from arginine derivatives in which both the amino and carboxyl groups were substituted and showed the highest activity towards Bz-L-Arg-O-Et among the arginine derivatives tested. The Km value for Bz-L-Arg-O-Et was found to be 0.50 X 10(-3) M. The enzyme also showed marked activities towards native protein substrates, such as protamine sulfate, soybean trypsin inhibitor, histone and bovine serum albumin.     

Purification and characterization of the extracellular alpha-amylase activity of the yeast Schwanniomyces alluvius

The extracellular alpha-amylase activity of the yeast Schwanniomyces alluvius has been purified by anion-exchange chromatography on DEAE-cellulose and gel-filtration chromatography on Sephadex G-100. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and N-terminal amino acid analysis of the purified sample indicated that the enzyme preparation was homogeneous. The enzyme is a glycoprotein having a molecular mass of 52 kilodaltons (kDa) estimated by SDS-PAGE and 39 kDa by gel filtration on Sephadex G-100. Chromatofocusing shows that it is an acidic protein. It is resistant to trypsin but sensitive to proteinase K. Its activity is inhibited by the divalent cation chelators EDTA and EGTA and it is insensitive to sulfhydryl-blocking agents. Exogenous divalent cations are inhibitory as are high concentrations of monovalent salts. The enzyme has a pH optimum between 3.75 and 5.5 and displays maximum stability in the pH range of 4.0-7.0. Under the conditions tested, the activity is maximal between 45 and 50 degrees C and is very thermolabile. Analysis of its amino acid composition supports its acidic nature.     

Purification and characterization of a plasminogen activator secreted by cultured human pancreatic carcinoma cells.

A plasminogen activator secreted by cultured human pancreatic carcinoma (Mia PaCa-2) cells has been purified to apparent homogeneity by procedures including Sepharose-L-arginine methyl ester affinity chromatography, Sephadex G-200 gel filtration, isoelectric focusing, and sodium dodecyl sulfate gel electrophoresis. The plasminogen activator shares many properties with urokinase including: molecular weight (55 000), isoelectric point (8.7), heat stability (60 degrees C, 30 min), PH stability (1.5-10), and its mode of activation of plasminogen. The intracellular enzyme is membrane bound and can be solubilized by detergent. Solubilized activator has a molecular weight similar to that of the secreted enzyme as determined by sodium dodecyl sulfate gel electrophoresis. The production of plasminogen activator by Mia PaCa-2 cells is totally inhibited by actinomycin D and cycloheximide.     

Isolation and characterization of an organic solvent soluble polypeptide component from photoreceptor complexes of Rhodospirillum rubrum.

An organic solvent soluble polypeptide has been isolated from photoreceptor complexes and chromatophores of Rhodospirillum rubrum. After extraction of the protein from lyophilized samples with 1:1 chloroform-methanol, it was purified by column chromatography. Its isoelectric point determined by isoelectric focusing was 7.10. When analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the purified polypeptide ran as a single band of an apparent molecular weight of 12 000. However, according to amino acid analysis, the minimal molecular weight based on one histidine residue per polypeptide is 19 000. The polypeptide contains no cysteine and no tyrosine. Amino acid analysis indicated that three methionines were present per histidine residue and cyanogen bromide cleavage gave four smaller peptides which were isolated by two-dimensional electrophoresis and chromatography. Spectroscopic analysis indicated the presence of three tryptophan residues per histidine and N-bromosuccinamide cleavage also gave four smaller peptides which could be isolated by two-dimensional electrophoresis and chromatography. The C-terminal amino acid was shown to be glycine by two methods, while the N-terminal amino acid appears to be blocked. The organic solvent soluble polypeptide accounts for approximately 50% of the chromatophore protein and seems to bind the antenna bacteriochlorophyll and carotenoid molecules. Using this procedure, organic solvent soluble polypeptides were isolated from several photosynthetic bacteria and were found to have substantially different amino acid contents.