Purification of p-hydroxyphenylpyruvate hydroxylase from rat liver—requirements for cofactors

1976 ◽  
Vol 54 (5) ◽  
pp. 423-431 ◽  
Author(s):  
Kun-Tsan Lin ◽  
John C. Crawhall
Keyword(s):  
Molecular Weight ◽  
Enzyme Activity ◽  
Rat Liver ◽  
Gel Filtration ◽  
Protein Band ◽  
Final Concentration ◽  
Assay Method ◽  
Enzyme Extract ◽  
Crude Enzyme Extract ◽  
Single Protein

Theenzyme p-hydroxyphenylpyruvate hydroxylase (EC 1.13.11.27)from rat liver was studied with the assay method which measures the release of 14CO2 from p-hydroxyphenyl [carboxyl-,14C]pyruvate. Extensive dialysis of the crude enzyme extract against Tris buffer or purification involving ammonium sulfate, gel filtration, and ion exchange results in loss of enzyme activity that can be reactivated by Fe2+, dichlorophenolindophenol, and various other agents. The effect of these activators depends critically on their final concentration in the assay media.A 70-fold purification of the enzyme fraction yielded a preparation which behaved as a single protein band in Sephadex G-150. It had an isoelectric point at 5.85 and molecular weight of 63 000. The enzyme obtained appears to be different in some respects from those described by other workers from the liver of dog, human, chicken, and frog.

scholarly journals Purification of NADPH-dependent dehydroascorbate reductase from rat liver and its identification with 3α-hydroxysteroid dehydrogenase

1994 ◽  
Vol 304 (2) ◽  
pp. 385-390 ◽  
Author(s):  
B Del Bello ◽  
E Maellaro ◽  
L Sugherini ◽  
A Santucci ◽  
M Comporti ◽  
...  
Keyword(s):  
Rat Liver ◽  
Gel Filtration ◽  
Dehydroascorbic Acid ◽  
Hydroxysteroid Dehydrogenase ◽  
Protein Band ◽  
Sds Page ◽  
Single Protein ◽  
Ammonium Sulphate Fractionation ◽  
Inflammatory Drugs ◽  
Rat Liver Cytosol

Rat liver cytosol has been found to reduce dehydroascorbic acid (DHAA) to ascorbic acid in the presence of NADPH. The enzyme responsible for such activity has been purified by ammonium sulphate fractionation, DEAE-Sepharose, Sephadex G-100 SF and Reactive Red column chromatography, with an overall recovery of 27%. SDS/PAGE of the purified enzyme showed one single protein band with an M(r) of 37,500. A similar value (36,800) was found by gel filtration on a Sephadex G-100 SF column. The results indicate that the enzyme is a homogeneous monomer. The Km for DHAA was 4.6 mM and the Vmax. was 1.55 units/mg of protein; for NADPH Km and Vmax. were 4.3 microM and 1.10 units/mg of protein respectively. The optimum pH was around 6.2. Several typical substrates and inhibitors of the aldo-keto reductase superfamily have been tested. The strong inhibition of DHAA reductase effected by steroidal and non-steroidal anti-inflammatory drugs, together with the ability to reduce 5 alpha-androstane-3,17-dione strongly, suggest the possibility that DHAA reductase corresponds to 3 alpha-hydroxysteroid dehydrogenase. Microsequence analysis performed on the electro-transferred enzyme band shows that the N-terminus is blocked. Internal primary structure data were obtained from CNBr-derived fragments and definitely proved the identity of NADPH-dependent DHAA reductase with 3 alpha-hydroxysteroid dehydrogenase.

Purification and characterization of exo-β-1,3-glucanase from a hatching supernatant of Strongylocentrotus intermedius

1983 ◽  
Vol 61 (1) ◽  
pp. 54-62 ◽  
Author(s):  
Kiyoshi Takeuchi
Keyword(s):  
Molecular Weight ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Protein Band ◽  
Divalent Ions ◽  
Purification And Characterization ◽  
Optimum Ph ◽  
Single Protein

Exo-β-1,3-glucanase from the sea urchin embryos was purified 114-fold from the initial hatching supernatant by the following procedures: (a) gel filtration on Sephadex G-100; (b) hydrophobic chromatography on 4-phenylbutylamine-Sepharose (PBA-Sepharose); (c) two ion-exchange chromatographic steps on DEAE-cellulose; (d) gel filtration on Ultrogel AcA 34; (e) gel filtration on Sephadex G-100. The purified enzyme contained 2.2% carbohydrate and gave a single protein band corresponding to a molecular weight of 136 000 following electrophoresis on sodium dodecyl sulfate (SDS) – urea – polyacrylamide gel. Gel filtration on Ultrogel AcA 34 with a nondenaturing solvent gave a molecular weight of 130 000 ± 6000. The enzyme displayed an optimum pH at 5.0–5.5 and hydrolysed laminarin and PS(curdlan)-beads at the nonreducing ends, releasing glucose. Although activity of the purified enzyme was not affected by SDS, urea, some divalent ions, and 2-mercaptoethanol, both dithiothreitol and Hg2+ were markedly inhibitory.

scholarly journals Rat liver alcohol dehydrogenase. Purification and properties

1971 ◽  
Vol 125 (4) ◽  
pp. 1039-1047 ◽  
Author(s):  
M J Arslanian ◽  
E Pascoe ◽  
J G Reinhold
Keyword(s):  
Molecular Weight ◽  
Alcohol Dehydrogenase ◽  
Rat Liver ◽  
Gel Filtration ◽  
Rabbit Antiserum ◽  
Minor Component ◽  
Disc Electrophoresis ◽  
Supernatant Fraction ◽  
Liver Alcohol Dehydrogenase ◽  
A Minor

Alcohol dehydrogenase (EC 1.1.1.1) from the rat liver supernatant fraction has been purified 200-fold and partially characterized. The isolation procedure involved ammonium sulphate fractionation, DEAE-Sephadex chromatography and gel filtration. The purified enzyme behaved as a homogeneous preparation as evaluated by cellulose acetate and polyacrylamide-gel disc electrophoresis. Sulphoethyl-Sephadex chromatography and immunoelectrophoresis with rabbit antiserum indicated the presence of a minor component. Rat liver alcohol dehydrogenase appears to contain 4mol of zinc/mol, has an estimated molecular weight of 65000 and consists of two subunits of similar molecular weight. Heavy-metal ions, thiol-blocking reagents, urea at concentrations below 8m, low pH (5.5) and chelating agents deactivate the enzyme but do not dissociate it into subunits. Deactivated enzyme could not be reactivated. The enzyme is strictly specific for NAD+ and has a broad specificity for alcohols, which are bound at a hydrophobic site. Inhibition occurred with the enzyme equilibrated with Zn2+ at concentrations above 0.1mm.

Purification of a Plasminogen Activator from Venous Occlusion Plasma

1979 ◽  
Author(s):  
B.R. Binder ◽  
J. Spragg
Keyword(s):  
Molecular Weight ◽  
Plasminogen Activator ◽  
Gel Filtration ◽  
Venous Occlusion ◽  
Blood Samples ◽  
Fibrin Plate ◽  
Human Volunteers ◽  
Weight Value ◽  
Purification Scheme ◽  
Single Protein

Following 15 minutes venous occlusion blood samples were drawn from human volunteers into EDTA and Polybrene as anticoagulants. The plasma of each donor (60-80mls) was fractionated by reverse (NH4)2SO4 gradient solubilization, elution from octyl-Sepharose with 50% ethylene glycol, and sequential gel filtration according to the method described for the purification of vascular plasminogen activator (Binder et al. JBC, 254, 1979, in press). A plasminogen activator (PA), demonstrately active on a plasminogen-rich but in active on a plasminogen-free fibrin plate, was purified by this procedure and characterized as having an apparent MW of 65.000-72.000, a pI of 8.0 - 8.3, and yielding a single protein stainable band on acid disk gels a t the region of PAactivity eluted from gels run in parallel. From the elution pat terns on the different columns used in the purification scheme, from the molecular weight value, the isoelectric point, and the mobility on acid polyacrylamide gels, it is concluded that the presently isolated and purified PA is identical to that already described as vascular plasminogen activator.

scholarly journals Identification of rat liver phosphatidylinositol synthase as a 21 kDa protein

1994 ◽  
Vol 304 (1) ◽  
pp. 301-305 ◽  
Author(s):  
M E Monaco ◽  
M Feldman ◽  
D L Kleinberg
Keyword(s):  
Heat Treatment ◽  
Enzyme Activity ◽  
Affinity Chromatography ◽  
Molecular Mass ◽  
Rat Liver ◽  
Protein Band ◽  
Absolute Requirement ◽  
Sds Page ◽  
Sepharose 4B ◽  
Post Mitochondrial Supernatant

Substantial purification of rat liver phosphatidylinositol (PtdIns) synthase has been achieved by a combination of Hecameg extraction, heat treatment, affinity chromatography and chromatography on PBE-94. The activity chromatographs as a single peak which has an apparent molecular mass between 150 and 200 kDa on Sepharose 4B. When analysed by SDS/PAGE, two major bands are seen. The enzyme activity is correlated with a protein band of 21 kDa. A second band, at 51 kDa, is eluted from a PBE-94 column slightly ahead of the activity. Manganese is an absolute requirement for stabilization of activity in the presence of detergent. The effect of manganese is optimal at 0.5 mM; magnesium at a concentration of 10 mM is only minimally effective. Substrate Kms are 1.3 mM and 9.5 microM for inositol and CDP-diacylglycerol respectively. The activity eluting from the PBE-94 column is purified 5000-fold over the post-mitochondrial supernatant.

Purification and Partial Characterization of Rat Liver Lipoxygenase

1987 ◽  
Vol 42 (10) ◽  
pp. 1343-1348 ◽  
Author(s):  
Pedro Macias ◽  
M. Carmen Pinto
Keyword(s):  
Molecular Weight ◽  
Enzyme Activity ◽  
Rat Liver ◽  
Polymorphonuclear Leukocytes ◽  
Fluorescence Spectra ◽  
Nordihydroguaiaretic Acid ◽  
Maximum Activity ◽  
Absorption And Fluorescence Spectra ◽  
Lipoxygenase Inhibitor

Abstract Lipoxygenase was purified from rat liver cytosolic fraction by a method involving two successive chromatographic steps on Sephacryl S-200 and Phenyl Sepharose CL-4B. The enzyme has a molecular weight of 96 Kdal and it seems to be composed of two identical subunits. Chromatofocusing of the enzyme revealed a single band of activity at pi 6.3. The enzyme activity of the purified fraction showed maximum activity at pH 7.0 with a Km for linoleic acid of 1.4 μM and is competitively inhibited by the specific lipoxygenase inhibitor nordihydroguaiaretic acid. The purified enzyme shows absorption and fluorescence spectra similar to those of lipoxygenase from other sources. However, the molecular weight of lipoxygenase purified from liver is found to be different from that of the enzyme from polymorphonuclear leukocytes. It is suggested that there are different isoenzymes of lipoxygenases in mammals.

scholarly journals A Low Molecular Weight Fibrinolytic Enzyme from Polymorphonuclear Leukocytes (PMN)

1977 ◽  
Author(s):  
L.A. Moroz
Keyword(s):  
Molecular Weight ◽  
Solid Phase ◽  
Degradation Products ◽  
Gel Filtration ◽  
Protein Band ◽  
Fibrinolytic Enzyme ◽  
Low Molecular Weight ◽  
Cationic Protein ◽  
Alkaline Proteinase ◽  
Solid Phase Assay

Despite evidence implicating PMN in fibrinolysis, the enzymes involved are incompletely characterized.PMN were prepared from normal blood by dextran sedimentation and fibrinolytic activity assayed by l25I-fibrin solid phase assay (Blood 46:543, 1975). More than 80% of activity was associated with intact PMN, was stimulated by Na salicylate (+65%, 20 mg/100 ml) and inhibited by α1-anti-trypsin (α1AT, -48%, 2 × 10-6 M). Similar activity was found in a PMN membrane fraction prepared by homogenization, differential centrifugation and Sepharose 4B gel filtration, from which fraction it was released by freeze-thawing and/or IM KCl treatment. Soluble enzyme activity was inhibited by of α1AT (-80%, 10-6 M), PMSF (-98%, 10-3 M), FeCl3 and ZnCl3 (-100%, 10-2 M), vitamin E(-38%, 10-4 M) and trypan blue (-40%, 10-3 M), but not by EACA (10-2 M), tranexamic acid (10-2 M), TLCK (10-3 M) or TPCK (10-3 M). This activity had an alkaline proteinase pH-activity profile, was localized to a single cationic protein band on acid Polyacrylamide disc gel electrophoresis, with pl of 8.6-8.7 by isoelectric focussing, and eluted between lysozyme and myoglobin on Bio-Gel P-10. On Bio-Gel A 0.5m and P-10, 125I-fibrin degradation products eluted after myoglobin. These findings indicate the presence in PMN of a low molecular weight, membrane-associated fibrinolytic enzyme of alkaline proteinase and serine active site type.

Mechanism of 67Ga Accumulation in Normal Rat Liver Lysosomes

1976 ◽  
Vol 15 (04) ◽  
pp. 185-194 ◽  
Author(s):  
A. Gebhardt ◽  
E. Schulz ◽  
U. Haubold ◽  
M. Hristowa ◽  
B. Zeggel ◽  
...  
Keyword(s):  
Rat Liver ◽  
Malignant Tumors ◽  
Gel Filtration ◽  
Normal Liver ◽  
Protein Band ◽  
Lysosomal Fraction ◽  
Coomassie Blue ◽  
Normal Rat ◽  
The Stability ◽  
Rat Liver Lysosomes

Summary 67Ga accumulates in various malignant tumors and parenchymatous tissues. It was found to be associated with the soluble fraction of lysosomes (11). The present work investigates the mechanism of 67Ga accumulation in normal liver cells.Lysosomes were isolated from rat liver after intravenous injection of carrier free 67Ga. The soluble lysosomal fraction was obtained by sonication followed by centrifugation at 105,000 xg for 2 hrs. Gel filtration on Sephadex G 25 superfine was carried out on the soluble lysosomal fraction in order to investigate the stability of the 67Ga-protein complex within the lysosomes under EDTA treatment. After treatment with 1 mM/1 EDTA a considerable amount of the protein bound radioactivity was found to be liberated. In further experiments the 67Ga binding lysosomal proteins were fractionated by electrophoresis on 7% Polyacrylamide gels (0.5 cm x 5.5 cm). After staining with Coomassie blue 18 separated protein bands were apparent. 67Ga distribution within the gels was assessed by direct counting of radioactivity in gel slices. A considerable amount of the intralysosomal protein bound radioactivity migrated with a relative mobility of 0.36 corresponding to a protein band of molecular weight 85,000 — 90,000. This peak corresponded to the peak of 67Ga labeled purified transferrin in control gels. These data were confirmed by Immunoelectrophoresis combined with autoradiography: within the soluble lysosomal fraction a slight transferrin line could be identified.We conclude that 67Ga which is transported in the blood by transferrin (23) and taken up by the hepatic cell through endocytosis (32) is accumulated in the lysosomes associated with transferrin and its degraded fragments.

scholarly journals Purification and characterization of glutathione-dependent dehydroascorbate reductase from rat liver

1994 ◽  
Vol 301 (2) ◽  
pp. 471-476 ◽  
Author(s):  
E Maellaro ◽  
B Del Bello ◽  
L Sugherini ◽  
A Santucci ◽  
M Comporti ◽  
...  
Keyword(s):  
Rat Liver ◽  
Protein Identification ◽  
Reductase Activity ◽  
Sequence Similarity ◽  
Gel Filtration ◽  
Dehydroascorbic Acid ◽  
Protein Band ◽  
Dehydroascorbate Reductase ◽  
Apparent Homogeneity ◽  
Sds Page

GSH-dependent enzymic reduction of dehydroascorbic acid to ascorbic acid has been studied in rat liver cytosol. After gel filtration of cytosol on Sephadex G-100 SF, dehydroascorbate reductase activity was recovered in two distinct peaks, one corresponding to glutaredoxin (an enzyme already known for its dehydroascorbate reductase activity) and another, much larger one, corresponding to a novel enzyme different from glutaredoxin. The latter was purified to apparent homogeneity. The purification process involved (NH4)2SO4 fractionation, followed by DEAE-Sepharose, Sephadex G-100 SF and Reactive Red chromatography. SDS/PAGE of the purified enzyme in either the presence or absence of 2-mercaptoethanol demonstrated a single protein band of M(r) 31,000. The M(r) determined by both Sephadex G-100 SF chromatography and h.p.l.c. was found to be approx. 48,000. H.p.l.c. of the denatured enzyme gave an M(r) value identical with that obtained by SDS/PAGE (31,000). The apparent Km for dehydroascorbate was 245 microM and the Vmax. was 1.9 mumol/min per mg of protein; for GSH they were 2.8 mM and 4.5 mumol/min per mg of protein respectively. The optimal pH range was 7.5-8.0. Microsequence analysis of the electro-transferred enzyme band showed that the N-terminus is blocked. Data on internal primary structure were obtained from CNBr-and N-chlorosuccinimide-derived fragments. No significative sequence similarity was found to any of the protein sequences contained in the Protein Identification Resource database.

scholarly journals Purification and photoaffinity labelling of lipid methyltransferase from rat liver

1984 ◽  
Vol 223 (1) ◽  
pp. 61-66 ◽  
Author(s):  
M A Pajares ◽  
S Alemany ◽  
I Varela ◽  
D Marin Cao ◽  
J M Mato
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Rat Liver ◽  
Short Wavelength ◽  
Protein Band ◽  
Catalytic Subunit ◽  
Photoaffinity Labelling ◽  
Methyl Donor ◽  
Single Protein Band ◽  
Single Protein

An enzyme that catalyses the three-step methylation of phosphatidylethanolamine to phosphatidylcholine as well as the methylation of fatty acids and that uses S-adenosylmethionine as the methyl donor has been purified about 200-fold from rat liver. Irradiation of the purified enzyme with a short-wavelength u.v. light in the presence of [methyl-3H]8-azido-S-adenosylmethionine followed by electrophoresis results in the incorporation of radioactivity into a single protein band of about 25 kDa. It is concluded that a single catalytic subunit catalyses the conversion of phosphatidylethanolamine into phosphatidylcholine and fatty acid methylation.

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