Purification and Characterization of an Unusual Aminopeptidase From Pea Seeds

1980 ◽  
Vol 7 (2) ◽  
pp. 131 ◽  
Author(s):  
JB Caldwell ◽  
LG Sparrow
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Sulfhydryl Group ◽  
Purification And Characterization ◽  
Apparent Homogeneity ◽  
Pea Seeds ◽  
Hydrolysis Of

An aminopeptidase with specificity for N-terminal glutamic and aspartic acid residues has been purified to apparent homogeneity from pea seeds (Pisum sativum cv. Greenfeast). It also catalyses the hydrolysis of the glutaryl-phenylalanine bond of the synthetic chymotrypsin substrate glutaryl- L-phenylalanine p-nitroanilide. The native enzyme, which has a molecular weight of approximately 500 000, gives a single band on polyacrylamide gel electrophoresis but two major bands when subjected to electrophoresis in the presence of sodium dodecyl sulfate after reduction. Its behaviour with various inhibitors suggests that a sulfhydryl group is important for its activity.

Purification and characterization of ferro- and cobalto-chelatases

1988 ◽  
Vol 66 (1) ◽  
pp. 32-39 ◽  
Author(s):  
Eduardo T. Cánepa ◽  
Elena B.C. Llambías
Keyword(s):  
Molecular Weight ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Purification And Characterization ◽  
Degree Of Unsaturation ◽  
Apparent Homogeneity ◽  
Optimum Ph ◽  
Single Protein ◽  
Metal Insertion

Pig liver ferrochelatase was purified 465-fold with about 30% yield, to apparent homogeneity, by a procedure involving solubilization from mitochondria, ammonium sulfate fractionation, and Sephacryl S-300 chromatography. The fraction of each purification step had cobaltochelatase as well as ferrochelatase activity. A purified protein of molecular weight 40 000 was found by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. A molecular weight of approximately 240 000 was obtained by Sephacryl S-300 chromatography. Both activities of the purified fraction increased linearly with time until 2 h. but nonlinear plots were obtained with increasing concentrations of protein. Their optimum pH values were similar. Km values were, for ferrochelatase activity, 23.3 μM for the metal and 30.3 μM for mesoporphyrin. and for cobaltochelatase activity. 27 and 45.5 μM, respectively. Fe2+ and Co2+ each protected against inactivation by heat. Pb2+, Zn2+, Cu2+, or Hg2+ inhibited both activities, while Mn2+ slightly activated; Mg2+ had no effect, at the concentrations tested. There appeared to be an involvement of sulfhydryl groups in metal insertion. Lipids, in correlation with their degree of unsaturation, activated both purified activities; phospholipids also had activation effects. We conclude that a single protein catalyzes the insertion of Fe2+ or Co2+ into mesoporphyrin.

Prothrombin Metz : Purification and Characterization of a Variant of Human Prothrombin

1979 ◽  
Author(s):  
M Ribieto ◽  
J Elion ◽  
D Labie ◽  
F Josso
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Factor Xa ◽  
Polyacrylamide Gel ◽  
Cleavage Pattern ◽  
Purification And Characterization ◽  
Double Immunodiffusion ◽  
The Family

For the purification of the abnormal prothrombin (Pt Metz), advantage has been taken of the existence in the family of three siblings who, being double heterozygotes for Pt Metz and a hypoprothrombinemia, have no normal Pt. Purification procedures included barium citrate adsorption and chromatography on DEAE Sephadex as for normal Pt. As opposed to some other variants (Pt Barcelona and Madrid), Pt Metz elutes as a single symetrical peak. By SDS polyacrylamide gel electrophoresis, this material is homogeneous and appears to have the same molecular weight as normal Pt. Comigration of normal and abnormal Pt in the absence of SDS, shows a double band suggesting an abnormal charge for the variant. Pt Metz exhibits an identity reaction with the control by double immunodiffusion. Upon activation by factor Xa, Pt Metz can generate amydolytic activity on Bz-Phe-Val-Arg-pNa (S2160), but only a very low clotting activity. Clear abnormalities are observed in the cleavage pattern of Pt Metz when monitored by SDS gel electrophoresis. The main feature are the accumulation of prethrombin l (Pl) and the appearance of abnormal intermediates migrating faster than Pl.

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.

scholarly journals Purification, characterization and radioimmunoassay of adenosine deaminase from human leukaemic granulocytes

1981 ◽  
Vol 195 (2) ◽  
pp. 389-397 ◽  
Author(s):  
D A Wiginton ◽  
M S Coleman ◽  
J J Hutton
Keyword(s):  
Molecular Weight ◽  
Adenosine Deaminase ◽  
Gel Electrophoresis ◽  
Specific Activity ◽  
Periodic Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Periodic Acid Schiff ◽  
Apparent Homogeneity

Adenosine deaminase was purified 3038-fold to apparent homogeneity from human leukaemic granulocytes by adenosine affinity chromatography. The purified enzyme has a specific activity of 486 mumol/min per mg of protein at 35 degrees C. It exhibits a single band when subjected to sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, non-denaturing polyacrylamide-gel electrophoresis and isoelectric focusing. The pI is 4.4. The enzyme is a monomeric protein of molecular weight 44000. Both electrophoretic behaviour and molecular weight differ from those of the low-molecular-weight adenosine deaminase purified from human erythrocytes. Its amino acid composition is reported. Tests with periodic acid-Schiff reagent for associated carbohydrate are negative. Of the large group of physiological compounds tested as potential effectors, none has a significant effect. The enzyme is specific for adenosine and deoxyadenosine, with Km values of 48 microM and 34 microM respectively. There are no significant differences in enzyme function on the two substrates. erythro-9-(2-Hydroxy non-3-yl) adenine is a competitive inhibitor, with Ki 15 nM. Deoxycoformycin inhibits deamination of both adenosine and deoxyadenosine, with an apparent Ki of 60-90 pM. A specific antibody was developed against the purified enzyme, and a sensitive radioimmunoassay for adenosine deaminase protein is described.

Purification and Characterization of an Acetyl Xylan Esterase from Bacillus pumilus

1998 ◽  
Vol 64 (2) ◽  
pp. 789-792 ◽  
Author(s):  
Giuliano Degrassi ◽  
Benedict C. Okeke ◽  
Carlo V. Bruschi ◽  
Vittorio Venturi
Keyword(s):  
Gel Electrophoresis ◽  
Bacillus Pumilus ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Acetyl Xylan Esterase ◽  
Purification And Characterization ◽  
Michaelis Constant ◽  
Naphthyl Acetate

ABSTRACT Bacillus pumilus PS213 was found to be able to release acetate from acetylated xylan. The enzyme catalyzing this reaction has been purified to homogeneity and characterized. The enzyme was secreted, and its production was induced by corncob powder and xylan. Its molecular mass, as determined by gel filtration, is 190 kDa, while sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed a single band of 40 kDa. The isoelectric point was found to be 4.8, and the enzyme activity was optimal at 55°C and pH 8.0. The activity was inhibited by most of the metal ions, while no enhancement was observed. The Michaelis constant (Km ) andV max for α-naphthyl acetate were 1.54 mM and 360 μmol min−1 mg of protein−1, respectively.

Purification and Characterization of a High-Molecular-Weight Insecticidal Protein Complex Produced by the Entomopathogenic BacteriumPhotorhabdus luminescens

1998 ◽  
Vol 64 (8) ◽  
pp. 3029-3035 ◽  
Author(s):  
David J. Bowen ◽  
Jerald C. Ensign
Keyword(s):  
Molecular Weight ◽  
Insecticidal Activity ◽  
Protein Complex ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Protein Toxin ◽  
The Family ◽  
Toxin Complex

ABSTRACT Photorhabdus luminescens is a gram-negative enteric bacterium that is found in association with entomopathogenic nematodes of the family Heterorhabditidae. The nematodes infect a variety of soil-dwelling insects. Upon entering an insect host, the nematode releases P. luminescens cells from its intestinal tract, and the bacteria quickly establish a lethal septicemia. When grown in peptone broth, in the absence of the nematodes, the bacteria produce a protein toxin complex that is lethal when fed to, or injected into the hemolymph of, Manduca sexta larvae and several other insect species. The toxin purified as a protein complex which has an estimated molecular weight of 1,000,000 and contains no protease, phospholipase, or hemolytic activity and only a trace of lipase activity. The purified toxin possesses insecticidal activity whether injected or given orally. Analyses of the denatured complex by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed it to be composed of several protein subunits ranging in size from 30 to 200 kDa. The complex was further separated by native gel electrophoresis into three components, two of which retained insecticidal activity. The purified native toxin complex was found to be active in nanogram concentrations against insects representing four orders of the classInsecta.

scholarly journals Purification and characterization of 3-dehydroquinase from Escherichia coli

1986 ◽  
Vol 239 (3) ◽  
pp. 699-704 ◽  
Author(s):  
S Chaudhuri ◽  
J M Lambert ◽  
L A McColl ◽  
J R Coggins
Keyword(s):  
Escherichia Coli ◽  
Gel Electrophoresis ◽  
Catalytic Properties ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Permeation Chromatography ◽  
Purification And Characterization ◽  
Gel Permeation

A procedure has been developed for the purification of 3-dehydroquinase from Escherichia coli. Homogeneous enzyme with specific activity 163 units/mg of protein was obtained in 19% overall yield. The subunit Mr estimated from polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate was 29,000. The native Mr, estimated by gel permeation chromatography on Sephacryl S-200 (superfine) and on TSK G3000SW, was in the range 52,000-58,000, indicating that the enzyme is dimeric. The catalytic properties of the enzyme have been determined and shown to be very similar to those of the biosynthetic 3-dehydroquinase component of the arom multifunctional enzyme of Neurospora crassa.

Acid and alkaline phosphatases of Capnocytophaga species. II. Isolation, purification, and characterization of the enzymes from Capnocytophaga ochracea

1983 ◽  
Vol 29 (10) ◽  
pp. 1361-1368 ◽  
Author(s):  
Thomas P. Poirier ◽  
Stanley C. Holt
Keyword(s):  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Alkaline Phosphatases ◽  
Purification And Characterization ◽  
Molecular Weights ◽  
Sds Page ◽  
Kinetics Of

Capnocytophaga ochracea acid (AcP; EC 3.1.3.2) and alkaline (AlP; EC 3.1.3.1) phosphatase was isolated by Ribi cell disruption and purified by sodium dodecyl sulphate – polyacrylamide gel electrophoresis (SDS–PAGE.) Both phosphatases eluted from Sephadex G-150 consistent with molecular weights (migration) of 140 000 and 110 000. SDS–PAGE demonstrated a 72 000 and 55 000 subunit molecular migration for AcP and AlP, respectively. The kinetics of activity of purified AcP and AIP on p-nitrophenol phosphate and phosphoseryl residues of the phosphoproteins are presented.

Prothrombin Metz: Purification and Characterization of a Variant of Human Prothrombin

1979 ◽  
Author(s):  
M.J. Rabiet ◽  
J. Elion ◽  
D. Labie ◽  
F. Josso
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Factor Xa ◽  
Polyacrylamide Gel ◽  
Cleavage Pattern ◽  
Purification And Characterization ◽  
Double Immunodiffusion ◽  
The Family

For the purification of the abnormal prothrombin (Pt Metz), advantage has been taken of the existence in the family of three siblings who, being double heterozygotes for Pt Metz and a hypoprothrombinemia, have no normal Pt. Purification procedures included barium citrate adsorption and chromatography on DEAE Sephadex as for normal Pt. As opposed to some other variants (Pt Barcelona and Madrid), Pt Metz elutes as a single symetrical peak. By SDS Polyacrylamide gel electrophoresis, this material is homogeneous and appears to have the same molecular weight as normal Pt. Comigration of normal and abnormal Pt in the absence of SDS, shows a double band suggesting an abnormal charge for the variant. Pt Metz exhibits an identity reaction with the control by double immunodiffusion.Upon activation by factor Xa, Pt Metz can generate amydolytic activity on Bz-Phe-Va1-Arg-pNa (S2160), but only a very low clotting activity. Clear abnormalities are observed in the cleavage pattern of Pt Metz when monitored by SDS gel electrophoresis. The main feature are the accumulation of prethrombin 1 (P1) and the appearance of abnormal intermediates migra-ti ng faster than P1.

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