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1.
Granulocyte-macrophage colony-stimulating factor (GM-CSF) was partially purified from post-endotoxin serum and conditioned media produced by organs from both normal and endotoxin-injected C57BL mice. The organs used to condition medium were heart, thigh muscle, salivary gland, thymus, spleen, kidney, brain, and femur shaft. The charge properties, molecular weights, and concanavalin A binding profiles of these GM-CSFs were analyzed and compared to purified mouse lung GM-CSF. All the GM-CSFs examined were shown to be gycoproteins since a proportion of the activity (80 to 100%) bound to concanavalin A-Sepharose. The organ-conditioned medium GM-CSFs were purified (3- to 13-fold) by absorption to calcium phosphate gel and chromatography on DEAE-Sepharose (further 2- to 10-fold). Analysis of the DEAE-Sepharose elution profiles indicated that there were two major charge species of GM-CSF eluting at conductivities of 10 and 14 mmho. These partially purified GM-CSFs showed considerable differences in their apparent molecular weights on Sephacryl S-200 (37,000 to 200,000). However, these differences could be eliminated by treating the GM-CSFs with neuraminidase and performing molecular sizing experiments under dissociating conditions (Sepharose CL-6B, 6 M guanidine hydrochloride). Although some of the GM-CSFs showed anomalously high molecular weights (40,000) on gel filtration columns, even under dissociating conditions, this appeared to be due to properties of the sialic acid residues. After neuraminidase treatment all of the conditioned medium GM-CSFs eluted from DEAE-Sepharose as a single peak of biological activity at a conductivity of 10 mmho and from gel filtration columns in the presence of 6 M guanidine hydrochloride as a single molecular weight species of approximately 23,000. GM-CSF from post-endotoxin serum (produced in vivo) eluted from the gel filtration column with an apparent molecular weight of 39,000, but analysis using polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate indicated that this GM-CSF also had an apparent molecular weight of 23,000.  相似文献   

2.
A low molecular weight 1,4-beta-glucan glucanohydrolase (endoglucanase) (1,4-(1,3;1,4)-beta-D-glucan 4-glucanohydrolase, EC 3.2.1.4) has been isolated from culture filtrates of the fungus Trichoderma viride QM 9414 by a two-step procedure of gel filtration and ion-exchange chromatography. The isolated enzyme appeared homogeneous upon polyacrylamide gel electrophoresis at pH 2.9, isoelectric focusing in a polyacrylamide gel slab, sedimentation equilibrium analysis and chromatography of the reduced and alkylated enzyme on a column of Sepharose 6B in 6 M guanidine - HCl. A molecular weight was calculated at approx. 20 000 and the isoelectric point was determined at pH 7.52. The purified enzyme was not a carbohydrate-containing protein.  相似文献   

3.
Polypeptide structure of DNA polymerase I from Saccharomyces cerevisiae   总被引:4,自引:0,他引:4  
DNA polymerase I of the yeast Saccharomyces cerevisiae has been purified to near homogeneity. The enzyme sediments under high salt conditions as a band at 7.4 S and two polypeptides of Mr = 140,000 and 110,000 are resolved by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Both polypeptides react with rabbit anti-yeast DNA polymerase I serum and can be shown to be enzymatically active by renaturation in situ after electrophoresis on polyacrylamide gels in the presence of sodium dodecyl sulfate. This high molecular weight form of yeast DNA polymerase I is very sensitive to inhibition by aphidicolin. The biochemical properties of the enzyme and inhibitors that may aid in distinguishing yeast DNA polymerases I and II are also described.  相似文献   

4.
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.  相似文献   

5.
Cytokinin binding protein from tobacco leaves was isolated and purified to a single protein by means of affinity chromatography on benzyladenine-linked Sepharose column combined with polyacrylamide gel electrophoresis. In vitro binding of this protein to [14C] benzyladenine was inhibited remarkably by cold benzyladenine and kinetin and slightly by adenine, but not adenosine. The molecular weight of the protein was determined to be about 4,000 daltons by gel filtration and SDS polyacrylamide gel electrophoresis.  相似文献   

6.
Second-step transfer of bacteriophage T5 DNA requires the function of the T5 pre-early proteins A1 and A2. We have isolated and characterized the gene A2 protein as part of an effort to determine the mechanism of second-step transfer. The A2 protein was purified by DNA-cellulose column chromatography followed by gel filtration and ion-exchange column chromatography. The A2 protein's identity was confirmed by two-dimensional gel electrophoresis. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and thin-layer gel filtration in 6 M guanidine hydrochloride demonstrated a molecular weight of 15,000 for the A2 polypeptide. Migration of the A2 protein through gel filtration columns under nondenaturing conditions, in combination with sedimentation behavior, indicated dimerization of the A2 polypeptide. The existence of the A2 dimer was confirmed by protein cross-linking with dimethyl suberimidate and analysis of the cross-linked proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The amino acid composition, degree of polymerization, DNA-binding ability, and physical characteristics of the T5 gene A2 protein are consistent with a function of the A2 protein in DNA transfer.  相似文献   

7.
Oxytocinase (cystyl-aminopeptidase) [EC 3.4.11.3] was isolated from monkey placenta in a purified form by a six-step prodedure comprising extraction from monkey placenta homogenate, ammonium sulfate fractionation, repeated chromatography on hydroxylapatite, chromatography on a column of DEAE-cellulose and gel filtration on a column of Sephadex G-200. The purified enzyme showed a single band on polyacrylamide disc electrophoresis. Oxytocin was inactivated by this enzyme preparation. The enzyme hydrolyzed several aminoacyl-beta-naphthylamides. A terminal amino group was required for enzyme activity. The molecular weight of the purified enzyme was estimated to be 87,000 by gel filtration and 83,000 by sodium dodecyl sulfate gel electrophoresis. Other properties of the enzyme, the effects of metal ions and various chemical reagents on the enzyme activity, the pH optimum, and Km values for a number of aminoacyl-beta-naphthylamides were also examined.  相似文献   

8.
N5-(L-1-Carboxyethyl)-L-ornithine:NADP+ oxidoreductase (EC 1.5.1.-) from Streptococcus lactis K1 has been purified 8,000-fold to homogeneity. The NADPH-dependent enzyme mediates the reductive condensation between pyruvic acid and the delta- or epsilon-amino groups of L-ornithine and L-lysine to form N5-(L-1-carboxyethyl)-L-ornithine and N6-(L-1-carboxyethyl)-L-lysine, respectively. The five-step purification procedure involves ion-exchange (DE52 and phosphocellulose P-11), gel filtration (Ultrogel AcA 44), and affinity chromatography (2',5'-ADP-Sepharose 4B). Approximately 100-200 micrograms of purified enzyme of specific activity 40 units/mg were obtained from 60 g of cells, wet weight. Anionic polyacrylamide gel electrophoresis revealed a single enzymatically active protein band, whereas three species (pI 4.8-5.1) were detected by analytical electrofocusing. The purified enzyme is active over a broad pH range of 6.5-9.0 and is stable to heating at 50 degrees C for 10 min. Substrate Km values were determined to be: NADPH, 6.6 microM; pyruvate, 150 microM; ornithine, 3.3 mM; and lysine, 18.2 mM. The oxidoreductase has a relative molecular mass (Mr = 150,000) as estimated by high pressure liquid chromatography exclusion chromatography and by polyacrylamide gradient gel electrophoresis. Conventional gel filtration indicated an Mr = 78,000, and a single protein band of Mr = 38,000 was revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme is composed of identical subunits of Mr = 38,000, which may associate to yield both dimeric and tetrameric forms. Polyclonal antibody to the purified protein inhibited enzyme activity. The amino acid composition of the enzyme is reported, and the sequence of the first 37 amino acids from the NH2 terminus has been determined by stepwise Edman degradation.  相似文献   

9.
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.  相似文献   

10.
Renin binding protein (RnBP) was purified from porcine kidney using pepstatin affinity column chromatography, DEAE-Sepharose column chromatography, gel filtration on Ultrogel-AcA 34, aminohexyl-Sepharose 4B column chromatography, and high performance liquid chromatography (HPLC) on TSK-gel G-3000 SW. The purified preparation was homogeneous as judged by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, polyacrylamide disc gel electrophoresis and isoelectric focusing on polyacrylamide gel. The isoelectric point was at pH 4.85, and the apparent molecular weight of RnBP was estimated to be 42,000 by SDS-polyacrylamide gel electrophoresis. The preparation did not show any renin activity and was stable for 30 min at 37 degrees C between pH 5.0 and 9.0 or on storage for 4 weeks at 4 degrees C or -80 degrees C. The activity of renin was greatly inhibited by RnBP. From the kinetic analysis of the inhibition we roughly estimated the dissociation constant between renin and RnBP to be about 0.2 nM, assuming that the stoichiometry in the complex, i.e., high molecular weight (HMW) renin, is one to one, and that the complex is inactive. The inhibitory activity of RnBP was lost by acidification at pH 3.0 and the activity of renin was restored. The purified RnBP formed a single precipitin line with the antiserum prepared with the purified HMW renin as antigen, which is RnBP-renin complex (Takahashi, S., et al. (1983) J. Biochem. 93, 265-274), and this line fused with one of the two precipitin lines formed between HMW renin and anti-HMW renin antiserum. The other of the two lines was between renin and anti-HMW renin antiserum. The purified preparation was thus identified as RnBP. The HMW renin was reconstituted with the purified RnBP and renin, and the apparent molecular weight of the reconstituted specimen was estimated to be 60,000 by gel filtration on Ultrogel AcA 44.  相似文献   

11.
A modified method for the detection of DNA polymerases in cell extracts and purified enzyme preparations after electrophoresis in polyacrylamide gradient cylindrical gels is described. The technique, which is based on direct assay of activity in a reaction mixture during elution of DNA polymerases from gel slices, was applied to the pursuit of enzyme forms of Streptomyces aureofaciens DNA polymerase during purification procedure. In a crude extract of S. aureofaciens mycelium many catalytically active forms of DNA polymerase ranging from 35 to 860 kDa were detected. After purification, that included mycelium homogenization, precipitation of nucleic acids by polyethylene glycol, DEAE-Sephadex, QAE-Sephadex and DNA-Sepharose chromatography, higher molecular mass forms of more than 172 kDa have not been found. The lower molecular mass forms were separated into two groups by DNA-Sepharose chromatography. On the basis of their characterization, it is assumed that the lower molecular mass forms are produced by proteolysis and the major form found after purification of S. aureofaciens DNA polymerase in the presence of suitable proteinase inhibitors should be a protein of 172 kDa.  相似文献   

12.
Highly active acid invertase was found in the young leaf extract of mandarin orange Citrus reticulata Blanco). The invertase was isolated and purified from the young leaf extract of mandarin orange through the procedures of ammonium sulphate precipitation, DEAE-Sepharose column chromatography and Sephacryl S-200 gel filtration. 6.4% of the invertase activity was recovered. Invertase was 179.2-folds purified. The purified invertase preparation was homogeneous as shown in polyacrylamide gel electrophoresis and Sephacryl S-200 molecular sieve chromatography. The molecular weight of the native invertase determined by gel filtration was 80 kD. The invertase consists of two identical subunits with apparent equal subunit weight of 40 kD as determined on SDS-PAGE. The invertase followed typical Michaelis-Menten Kinetics with apparent Km Of 1. 6 × 10-2 mol/L for sucrose. Vmax of the invertase was 100 mg reducing sugar · mg-1 protein · h-1 The optimum pH was 5.0 (stable from 4.5—5.5). The optimum temperature was 55℃.  相似文献   

13.
Alkaline phosphatase of cultured rat ascites hepatoma cells has been purified by butanol extraction, DEAE-cellulose column chromatography, gel filtration through Sephadex G-200, concanavalin A-Sepharose affinity chromatography, and polyacrylamide gel electrophoresis. Affinity chromatography confirmed the glycoprotein nature of alkaline phosphatase from cultured rat ascites hepatoma cells. Electrophoresis on polyacrylamide gels of various concentrations indicated a molecular weight of 290,000. The molecular weight of the subunit was estimated to be 72,000 by SDS-polyacrylamide gel electrophoresis. These findings suggest that alkaline phosphatase of cultured rat ascites hepatoma cells is a tetramer with a subunit molecular weight of 72,000.  相似文献   

14.
A trypsin-like oviducal proteinase acting upon the vitelline envelope of Bufo arenarum coelomic oocytes has been purified to apparent homogeneity by gel filtration on Sephadex G-200 and by affinity chromatography on a column of Sepharose 4-B containing covalently bound concanavlin A (Con A). The biologically active molecule migrated as a single band of protein upon SDS polyacrylamide gel electrophoresis.  相似文献   

15.
Previous work has demonstrated that the activity of the enzyme cholesterol sulfotransferase is rapidly and dramatically increased upon squamous differentiation of a variety of epithelial cells in culture, including epidermal keratinocytes. As a step toward understanding the molecular mechanisms underlying this differentiation-related change, we now report the partial purification and characterization of this enzyme activity from rat skin. Supernatant solutions from rat skin homogenates were subjected to a series of column chromatography steps including anion exchange, gel filtration, chromatofocusing and hydrophobic interaction chromatography. The purification procedure resulted in cholesterol sulfotransferase activity purified 2,700-fold with a 11% recovery. The most purified preparation yielded a major Coomassie blue-stained band on denaturing polyacrylamide gel electrophoresis of an apparent molecular weight (MW) of 40,000 Da. Photoaffinity labeling with the donor substrate, 3'-phosphoadenosine-5'-phospho-[35S]-sulfate resulted in a single radiolabeled protein band on denaturing polyacrylamide gel electrophoresis, again of apparent MW 40,000 Da, strongly suggesting that the major Coomassie blue-stained band in the most purified preparation is the cholesterol sulfotransferase protein. Among 3beta-hydroxysteroids with a A5 double bond that were tested, each served as a substrate, while androgens, estrogens, corticosteroids, p-nitrophenol and DOPA did not serve as substrates. Apparent Michaelis constants for the 3beta-hydroxysteroid substrates ranged from 0.6 to 8 microM.  相似文献   

16.
Two antigenically active glycoprotein fractions were isolated from crude extract of the pollen of Prosopis juliflora using DEAE-cellulose ion exchange chromatography. The glycoproteins gave single band on polyacrylamide gel electrophoresis. The molecular weight of these two glycoprotein was 20,000 and 10,000 as determined by gel filtration on Sephadex G-75. With the help of crossed immunoelectrophoresis and gel diffusion crude extract exhibited twelve and three precipitating antigens suggesting its heterogeneous nature; and the purified glycoprotein fractions however formed single precipitin band on gel diffusion test and immunoelectrophoresis. As tested by ELISA the polyclonal antisera raised in rabbit showed strong binding affinity with glycoprotein of MW 20,000. These result indicates that the two glycoprotein fractions are not antigenically identical.  相似文献   

17.
A protease was purified 163-fold from Pronase, a commercial product from culture filtrate of Streptomyces griseus, by a series of column chromatographies on CM-Toyopearl (Fractogel), Sephadex G-50, hydroxyapatite, and Z-Gly-D-Phe-AH-Sepharose 4B using Boc-Ala-Ala-Pro-Glu-pNA as a substrate. The final preparation was homogeneous by polyacrylamide gel electrophoresis (PAGE), sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and gel isoelectric focusing. Studies on the substrate specificity with peptide p-nitroanilides revealed that this protease preferentially hydrolyzed peptide bonds on the carbonyl-terminal side of either glutamic acid or aspartic acid. It was most active at pH 8.8 for the hydrolysis of Boc-Ala-Ala-Pro-Glu-pNA. The molecular weight of the protease was estimated to be 20,000 by gel filtration on Sepharose 6B using 6 M guanidine hydrochloride as an eluent, and 22,000 by SDS-PAGE in the presence of 2-mercaptoethanol. The isoelectric point of the enzyme was 8.4. The enzyme was inactivated by diisopropyl phosphofluoridate (DFP) but not by p-chloromercuribenzoate (PCMB) or EDTA.  相似文献   

18.
Cyclic nucleotide phosphodiesterase from calf myometrium has been purified to a homogeneous state for the first time, as can be evidenced from polyacrylamide gel electrophoresis data. The purification procedure included ion-exchange chromatography on DEAE-cellulose, high pressure liquid chromatography on TSK 545 DEAE and gel filtration through Toyopearl HW-55. The molecular mass of the enzyme as determined by gel filtration and polyacrylamide gel electrophoresis is 110 kD. The purified enzyme hydrolyzes cAMP and cGMP with Km = 30 microM and 18 microM, respectively.  相似文献   

19.
A lectin was purified to homogeneity from the mushroom, Flammulina veltipes, by zinc acetate treatment and CM-cellulose column chromatography. Its molecular weight was estimated to be 20,000 by gel filtration and polyacrylamide gel electrophoresis. The lectin does not contain carbohydrate, half-cystine, methionine, or histidine. On gel filtration sith Sepharose 6B in the presence of 6M guanidine-HCl, the purified lectin dissociated into two nonidentical subunits, FVA-L (molecular weight, 12,000) and FVA-S (8,000). The hemagglutinating activity was retained only in the FVA-L subunit. The lectin is mitogenic with respect to mouse spleen lymphocytes.  相似文献   

20.
The trehalase of Chaetomium aureum was purified about 196-fold with a yield of 51% from the culture filtrate by ammonium sulfate fractionation, DEAE-cellulose column chromatography, acetone fractionation, and Sephadex G-100 gel filtration. The enzyme preparation was homogeneous on disc electrophoresis. The enzyme was most active at pH 4.0 and 50°C. The enzyme was stable from pH 4.0 to 9.0 on 12 h incubation at 37°C. The molecular weight of the enzyme was estimated to be 450,000 by gel filtration on a column of Sepharose 6B, and 115,000 by SDS polyacrylamide gel electrophoresis. This indicated that the enzyme might consist of 4 subunits. The isoelectric point of the enzyme was pH 4.0. The enzyme was active specifically on trehalose and not active on the other disaccharides tested.  相似文献   

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