scholarly journals Purification of the high-Km aldehyde reductase from rat brain and liver and from ox brain

1981 ◽  
Vol 197 (2) ◽  
pp. 473-481 ◽  
Author(s):  
A J Rivett ◽  
I L Smith ◽  
K F Tipton
Keyword(s):  
Rat Brain ◽  
Rat Liver ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Kinetic Properties ◽  
Aldehyde Reductase ◽  
Purification Procedure ◽  
Electrophoretic Mobilities ◽  
Rat Brain And Liver ◽  
Homogeneous Preparation

A procedure is described that yields an apparently homogeneous preparation of the high-Km aldehyde reductase from rat brain. This procedure is also applicable to the purification of this enzyme from rat liver and ox brain. In the latter case, however, the purified preparation could be resolved into two protein bands, both of which had enzyme activity, by polyacrylamide-gel electrophoresis. Since a sample of the ox brain enzyme from an earlier step in the purification procedure only showed the presence of a single band of activity after electrophoresis, this apparent multiplicity probably results from modification of the enzyme, possibly by oxidation, during the final step of the purification. A number of properties of the rat brain enzyme were determined and these were compared with those of the enzyme from rat liver. The two preparations were similar in their stabilities, behaviour during purification, kinetic properties, electrophoretic mobilities and amino acid compositions. Antibodies to the rat liver enzyme cross-reacted with that from brain and the inhibition of both these preparations by the antiserum was similar, further supporting the view that the enzymes from these two sources were closely similar if not identical.

scholarly journals Purification and properties of arginase from human liver and erythrocytes

1978 ◽  
Vol 175 (2) ◽  
pp. 449-454 ◽  
Author(s):  
J Berüter ◽  
J P Colombo ◽  
C Bachmann
Keyword(s):  
Gel Electrophoresis ◽  
Human Liver ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Sedimentation Coefficient ◽  
Polyacrylamide Gel ◽  
Kinetic Properties ◽  
Purification Procedure

Arginase was isolated from human liver and erythrocytes. The purification procedure used acetone precipitation, heat-treatment, (NH4)2SO4 precipitation, DEAE-cellulose chromatography and gel filtration on Sephadex G-200 in the presence of 2-mercaptoethanol. Both enzymes migrated to the anode at pH8.3 on polyacrylamide-gel electrophoresis. After incubation at pH8.0 and 37 degrees C the purified anionic liver arginase migrated to the cathode on polyacrylamide-gel electrophoresis. It is assumed that the multiple forms of the enzyme reported in the literature are partly artifacts of the purification procedure. The liver arginase showed a mol.wt. of 107000 determined by gel filtration and a sedimentation coefficient of 5.9S. Treatment of the liver enzyme with 0.25% sodium dodecyl sulphate at pH10 demonstrated an oligomeric structure of the enzyme with a mol.wt. of the subunit of 35000. The kinetic properties determined for the purified liver arginase showed an optimum pH of 9.3 and an optimal MnCl2 concentration of 2mM. The Km for L-arginine was 10.5 mM and for L-canavanine 50mM, and L-lysine exhibited a competitive type of inhibition with a Ki of 4.4mM. L-Homoarginine was not a substrate for liver arginase.

Purification and partial characterization of cysteine-glutamate transaminase from rat liver

1977 ◽  
Vol 55 (9) ◽  
pp. 958-964 ◽  
Author(s):  
M. P. C. Ip ◽  
R. J. Thibert ◽  
D. E. Schmidt Jr.
Keyword(s):  
Molecular Weight ◽  
Rat Liver ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Liver Homogenate ◽  
Polyacrylamide Gel ◽  
Gel Chromatography ◽  
Labile Hydrogen ◽  
Apparent Homogeneity

Cysteine-glutamate transaminase (cysteine aminotransferase; EC 2.6.1.3) has been purified 149-fold to an apparent homogeneity giving a specific activity of 2.09 IU per milligram of protein with an overall yield of 15%. The isolation procedures involve the preliminary separation of a crude rat liver homogenate which was submitted sequentially to ammonium sulfate fractionation, TEAE-cellulose column chromatography, ultrafiltration, and isoelectrofocusing. The final product was homogenous when examined by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS). A minimal molecular weight of 83 500 was determined by Sephadex gel chromatography. The molecular weight as estimated by polyacrylamide gel electrophoresis in the presence of SDS was 84 000. The purified enzyme exhibited a pH optimum at 8.2 with cysteine and α-ketoglutarate as substrates. The enzyme is inactivated slowly when kept frozen and is completely inactivated if left at room temperature for 1 h. The enzyme does not catalyze the transamination of α-methyl-DL-cysteine, which, when present to a final concentration of 10 mM, exhibits a 23.2% inhibition of transamination of 30 mM of cysteine. The mechanism apparently resembles that of aspartate-glutamate transaminase (EC 2.6.1.1) in which the presence of a labile hydrogen on the alpha-carbon in the substrate is one of the strict requirements.

Isoperoxidases of (IAA oxidase) oxidase in oat coleoptiles

1973 ◽  
Vol 51 (11) ◽  
pp. 2047-2052 ◽  
Author(s):  
William R. Gordon ◽  
James H. M. Henderson
Keyword(s):  
Acetic Acid ◽  
Avena Sativa ◽  
Gel Electrophoresis ◽  
Enzyme Assay ◽  
Polyacrylamide Gel Electrophoresis ◽  
Acid Oxidase ◽  
Iaa Oxidase ◽  
Substrate Specificities ◽  
Electrophoretic Mobilities ◽  
Indole 3 Acetic Acid

Eight constitutive isoperoxidases were separated by the disc method of polyacrylamide gel electrophoresis from a lyophilized extract of 8-day-old oat (Avena sativa L., cv. Victory) coleoptiles. Both anodic and cathodic isoperoxidases were studied and differences in electrophoretic mobilities and hydrogen donor substrate specificities were revealed. In addition, by enzyme assay, cathodic and anodic isoenzymes were shown to possess differences in peroxidase and IAA (indole-3-acetic acid) oxidase activities.Treatment of coleoptiles with 0.07 mM IAA for 24 h resulted in the repression of two slow-migrating anodic isoperoxidases; however, the same treatment also resulted in the induction of two slow-migrating cathodic isoenzymes which were shown to exhibit peroxidase and IAA oxidase activities.

A three step purification procedure for human liver ferritin

1980 ◽  
Vol 58 (6) ◽  
pp. 494-498 ◽  
Author(s):  
M. Pagé ◽  
J. Lagueux ◽  
C. Gauthier
Keyword(s):  
Affinity Chromatography ◽  
Gel Electrophoresis ◽  
Human Liver ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Purification Procedure ◽  
Human Liver Ferritin ◽  
Normal Human Liver ◽  
Normal Human ◽  
Liver Ferritin

We describe a method for the purification of normal human liver ferritin by ultrafiltration, gel filtration on Sephacryl S-300, and affinity chromatography on DEAE-Affi Gel Blue. The purity of the ferritin obtained was verified by immunoelectrophoresis, Ouchterlony immunodiffusion, polyacrylamide gel electrophoresis, and electrofocusing. This rapid method yields 32% of the original ferritin.

scholarly journals Inhibition of the thrombin–fibrinogen reaction by a macromolecular factor from rat liver

1972 ◽  
Vol 129 (1) ◽  
pp. 83-89 ◽  
Author(s):  
Ragnar Flengsrud ◽  
Bjarne Østerud ◽  
Hans Prydz
Keyword(s):  
Molecular Weight ◽  
Rat Liver ◽  
Gel Electrophoresis ◽  
Competitive Inhibition ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Liver Homogenate ◽  
Kinetic Studies ◽  
Disc Electrophoresis ◽  
Nitrobenzoic Acid

1. The supernatant obtained by centrifugation of a rat liver homogenate at 100000g for 1h contained a heat-labile macromolecular inhibitor of the thrombin–fibrinogen reaction. 2. The inhibitor was purified to electrophoretic homogeneity by repeated preparative polyacrylamide disc electrophoresis. Inhibition was observed with purified inhibitor equivalent to about 1μg of protein/ml. 3. The inhibitor had a pI of 3.50–3.75, a molecular weight (from sodium dodecyl sulphate–polyacrylamide-gel electrophoresis) of 72000±3000 and was inactivated by p-hydroxymercuribenzoate or 5,5′-dithiobis-(2-nitrobenzoic acid). 4. Kinetic studies revealed a non-competitive inhibition, with the inhibitor probably acting on the thrombin–fibrinogen complex.

scholarly journals Phosphoenolpyruvate carboxylase from the crassulacean plant Bryophyllum fedtschenkoi Hamet et Perrier. Purification, molecular and kinetic properties

1978 ◽  
Vol 175 (2) ◽  
pp. 391-406 ◽  
Author(s):  
R Jones ◽  
M B Wilkins ◽  
J R Coggins ◽  
C A Fewson ◽  
A D B Malcolm
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Gel Electrophoresis ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Deae Cellulose ◽  
Maximum Velocity ◽  
Single Band ◽  
Kinetic Properties ◽  
Subunit Structure

Phosphoenolpyruvate carboxylase from the Crassulacean plant Bryophyllum fedtschenkoi has been purified to homogenetity by DEAE-cellulose treatment, (NH4)2SO4 fractionation,, and chromatography on DEAE-cellulose and hydroxyapatite. Poly(ethylene glycol) is required in the extraction medium to obtain maximum enzyme activity. The purified enzyme has a specific activity of about 26 units/mg of protein at 25 degrees C. It gives a single band on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, corresponding to a mol.wt. of 105,000, and gives a single band on non-denaturing gel electrophoresis at pH8.4. Cross-linking studies at pH8.0 indicate that the subunit structure is tetrameric but that the dimer may also be an important unit of polymerization. Gel filtration results at pH6.7 confirm that the native enzyme is tetrameric with a concentration-dependent dissociation to a dimer. The kinetic behaviour is characterized by (i) relatively small variations in maximum velocity between pH5.5 and 9.0 with a double optimum, (ii) a reversible temperature-dependent inactivation between 30 and 45 degrees C, (iii) inhibition by malate, which is pH-sensitive, and (iv) almost Michaelis-Menten behaviour with phosphoenolpyruvate as the varied ligand but sigmoidal behaviour under suitable conditions with malate as the varied ligand. The findings are related to other studies to the possible role phosphoenolpyruvate carboxylase in controlling a circadian rhythm of CO2 fixation.

scholarly journals Affinity-chromatographic purification of S-adenosyl-l-homocysteine hydrolase. Some properties of the enzyme from rat liver

1981 ◽  
Vol 193 (2) ◽  
pp. 503-512 ◽  
Author(s):  
E O Kajander ◽  
A M Raina
Keyword(s):  
Rat Liver ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Adenosine Kinase ◽  
Native Enzyme ◽  
Apparent Homogeneity ◽  
A Subunit ◽  
Adenosine Derivatives ◽  
Pore Gradient

S-Adenosyl-L-homocysteine hydrolase has been purified to apparent homogeneity from rat liver by means of affinity chromatography on 8-(3-aminopropylamino)adenosine linked to Sepharose. The purified enzyme was free from adenosine kinase and adenosine deaminase activities and was homogeneous on SDS/polyacrylamide-gel electrophoresis which gave a subunit mol.wt. of 47 000. The native enzyme showed some microheterogeneity on polyacrylamide-gel electrophoresis under increased-resolution conditions but was homogeneous on isoelectric focusing (pI 5.6). The molecular weight of the native enzyme was about 220 000 as judged by pore-gradient electrophoresis. The native enzyme bound adenosine tightly and showed Km values of 0.6 microM, 0.9 microM and 60 microM for adenosine, S-adenosyl-L-homocysteine and L-homocysteine respectively. The enzyme was rapidly inactivated when incubated in the presence of adenosine, S-adenosyl-L-homocysteine or several adenosine derivatives or analogues. Inactivation took place both at 0 and 37 degrees C. Freezing in the absence of glycerol resulted in the appearance of dissociation products of the oligomeric protein. Multimer formation was observed at low thiol concentrations.

Rat liver ribonucleotide reductase: separation, purification, and properties of two nonidentical subunits

1982 ◽  
Vol 60 (4) ◽  
pp. 463-470 ◽  
Author(s):  
T. Youdale ◽  
J. P. MacManus ◽  
J. F. Whitfield
Keyword(s):  
Rat Liver ◽  
Ribonucleotide Reductase ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Deae Cellulose ◽  
Polyacrylamide Gel ◽  
Relative Mass ◽  
Purification And Properties ◽  
Exclusion Chromatography

Two nonidentical subunits of mammalian ribonucleotide reductase, L1 and L2, from regenerating rat liver have been extensively purified for the first time. They were separated by dATP-Sepharose affinity chromatography. Subunit L1, which bound to dATP-Sepharose, was eluted with 50 mM ATP and purified to homogeneity (as demonstrated by sodium dodecyl sulfate (SDS) – polyacrylamide gel electrophoresis) by molecular exclusion high-pressure liquid chromatography (HPLC). This subunit had an apparent relative mass (Mr) of 45 000 and a Km of 0.9 × 10−4 for CDP. Subunit L2, which did not bind to dATP-Sepharose, was purified by pH 5.2 precipitation followed by chromatography on CM-Sephadex, molecular exclusion HPLC, and DEAE-cellulose. This subunit contained iron and had an apparent Mr of 120 000 by HPLC molecular exclusion chromatography, but showed two bands (Mr 75 000 and Mr 47 000) on SDS–polyacrylamide gel electrophoresis. Neither L1 nor L2 separately had any enzyme activity but when combined they reduced CDP to dCDP.

scholarly journals HMG (high-mobility-group)-14/17-like proteins in calf thyroid. Thyrotropin-dependent phosphorylation and comparison with calf thymus proteins

1983 ◽  
Vol 215 (3) ◽  
pp. 643-649 ◽  
Author(s):  
E Cooper ◽  
S W Spaulding
Keyword(s):  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
High Mobility ◽  
High Mobility Group ◽  
Group 14 ◽  
Sephadex Column ◽  
High Mobility Group Proteins ◽  
Electrophoretic Mobilities ◽  
Calf Thymus ◽  
Thymus Tissue

Two-dimensional polyacrylamide-gel electrophoresis of acid extracts of thyroid and thymus tissue, and of thyroid nuclei, revealed the presence of three HClO4-soluble nuclear proteins, PS.1, PS.2 and PS.3, whose electrophoretic mobilities closely resembled those of HMG (high-mobility-group) proteins 14 and 17. PS.1 co-migrated with HMG 14 on CM-Sephadex column chromatography. Like HMG 14, PS.2 and PS.3 were phosphorylated in calf thyroid slices; 32P-labelling of PS.3 was stimulated by thyrotropin. Thyrotropin also induced a rapid increase in the labelling of A5, an HMG-14/17-like protein found in whole calf thyroid and thymus tissue, but not in thyroid nuclei.

scholarly journals Purification and characterization of histidine decarboxylase from mouse kidney

1986 ◽  
Vol 234 (2) ◽  
pp. 349-354 ◽  
Author(s):  
S A M Martin ◽  
J O Bishop
Keyword(s):  
Column Chromatography ◽  
Gel Electrophoresis ◽  
Histidine Decarboxylase ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Mouse Kidney ◽  
Purification Procedure ◽  
Purification And Characterization ◽  
A Subunit

Histidine decarboxylase was purified 800-fold from the kidneys of thyroxine-treated mice. The purification procedure included precipitation of protein from a crude supernatant after heating it to 55 degrees C at pH 5.5, fractionation with (NH4)2SO4, phosphocellulose column chromatography, chromatofocusing, DEAE-Sepharose column chromatography, gel filtration on Sephacryl S-300 and preparative polyacrylamide-gel electrophoresis. The native enzyme had an estimated Mr of 113 000. The protein was analysed in SDS/10%-polyacrylamide gels and formed a single band corresponding to a subunit Mr of 55 000, indicating that it is a dimer. Three forms of the enzyme were resolved on isoelectrofocusing gels, with pI 5.3, 5.5 and 5.7.

Sign in / Sign up

Export Citation Format

Share Document