scholarly journals A simple method for purification of epoxide hydratase from rat liver

1977 ◽  
Vol 163 (2) ◽  
pp. 381-383 ◽  
Author(s):  
R G Knowles ◽  
B Burchell

Rat liver epoxide hydratase was purified 460-fold to homogeneity by detergent solubilization and ion-exchange chromatography. The enzyme obtained in high yield (36%) exhibited a specific activity of 479nmol of styrene glycol formed/min per mg of protein, with styrene oxide as substrate. Only one polypeptide-staining band, mol.wt. 49500, was visible after sodium dodecyl sulphate/polyacrylamide-gel electrophoresis.

2021 ◽  
Vol 13 (2) ◽  
pp. 107-112
Author(s):  
C.F. Okechukwu ◽  
P.L. Shamsudeen ◽  
R.K. Bala ◽  
B.G. Kurfi ◽  
A.M. Abdulazeez

The most effective and acceptable therapy for snakebite victims is the immediate administration of antivenin which is limited by problems of hypersensitivity reactions in some individuals and its inability to resolve the local effects of the venom. The aim of this study was to isolate, partially purify and characterize phospholipase A2 from Naja Katiensis venom. Phospholipase A2 was partially purified via a two-step process: gel filtration on Sephadex G-75 and ion exchange chromatography using CM Sephadex, and subjected to SDS-PAGE analysis. From the results, the specific activity of the partially purified PLA2 decreased from 0.67μmol/min/mg in crude venom to 0.29μmol/min/mg after ion exchange chromatography with a yield of 5% and purification fold of 0.43. The optimum temperature of the purified PLA2 was found to be 35ºC and optimum p.H of 7. velocity studies for the determination of kinetic constants using L-a-lecithin as substrate revealed a Km  of 1.47mg/ml and Vmax  of 3.32μ moles/min/mg. The sodium dodecyl sulphate polyacrylamide gel electrophoresis of the purified PLA2 showed a distinct band with molecular weight estimated to be 14KDa. In conclusion, the present study shows that phospholipase A2 was isolated, purified and characterized. This may serve as a promising candidate for future development of a novel anti-venin drug.


1981 ◽  
Vol 195 (1) ◽  
pp. 159-165 ◽  
Author(s):  
T E Cawston ◽  
W A Galloway ◽  
E Mercer ◽  
G Murphy ◽  
J J Reynolds

1. Rabbit bones in tissue culture synthesize an inhibitor of collagenase during the first 4 days of culture. 2. The inhibitor was purified by a combination of gel filtration, concanavalin A--Sepharose chromatography, ion-exchange chromatography and zinc-chelate affinity chromatography. 3. The purified inhibitor migrated as a single band on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and had a mol.wt. of 28000. 4. The inhibitor blocked the activity of the metalloproteinases collagenase, gelatinase, neutral proteinase III (proteoglycanase), human leucocyte collagenase and gelatinase, but not thermolysin or bacterial collagenase. The serine proteinases plasmin and trypsin were not inhibited. 5. The inhibitor interacted with purified rabbit bone collagenase with 1:1 stoichiometry. 6. The inhibitory activity was lost after incubation for 1 h at 90 degrees C, after treatment with trypsin (250 micrograms/ml) at 37 degrees C for 30 min and after reduction and alkylation.


1975 ◽  
Vol 53 (11) ◽  
pp. 1150-1157 ◽  
Author(s):  
P. M. Strasberg ◽  
K. B. Freeman

Proteins of the rat liver mitochondrial matrix have been separated into anionic (acidic), cationic (basic), and neutral groups by electrophoresis. These groups represent 69, 8, and 23% of the total matrix protein, respectively, compared to 69, 21, and 10% for the cytosol protein. The acidic nature of the mitochondrial matrix proteins has been confirmed by cellulose ion-exchange chromatography, isoelectric focusing in sucrose gradients, and amino acid analysis. The anionic, cationic, and neutral matrix proteins were separated by sodium dodecyl sulfate – polyacrylamide gel electrophoresis into 18, 6, and 5 bands, respectively, compared to 22 bands for the total fraction. The significance of the charge properties of these proteins in terms of mitochondrial biogenesis is discussed.


1999 ◽  
Vol 65 (10) ◽  
pp. 4682-4684 ◽  
Author(s):  
Tadashi Nagashima ◽  
Tatsuya Tange ◽  
Hideharu Anazawa

ABSTRACT A phytase (EC 3.1.3.8 ) with a high affinity for phytic acid was found in Aspergillus niger SK-57 and purified to homogeneity in four steps by using ion-exchange chromatography (two types), gel filtration, and chromatofocusing. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified enzyme gave a single stained band at a molecular mass of approximately 60 kDa. The Michaelis constant of the enzyme for phytic acid (18.7 ± 4.6 μM) was statistically analyzed. In regard to the orthophosphate released from phytic acid, a significant difference between a lowKm phytase from A. niger SK-57 and a high Km phytase from Aspergillus ficuum was recognized.


1998 ◽  
Vol 44 (7) ◽  
pp. 646-651 ◽  
Author(s):  
N Mathivanan ◽  
V Kabilan ◽  
K Murugesan

Chitinase (EC 3.2.1.14) was isolated from the culture filtrate of Fusarium chlamydosporum and purified by ion-exchange chromatography and gel filtration. The molecular mass of purified chitinase was 40 kDa as estimated by sodium dodecyl sulfate – polyacrylamide gel electrophoresis. Chitinase was optimally active at a pH of 5 and stable from pH 4 to 6 and up to 40°C. Among the metals and inhibitors tested, mercuric chloride completely inhibited the enzyme activity. The activity of chitinase was high on colloidal and pure chitin. The purified chitinase inhibited the germination of uredospores of Puccinia arachidis and also lysed the walls of uredospores and germ tubes. The results from these experiments indicated that chitinase of F. chlamydosporum plays an important role in the biocontrol of groundnut rust. Key words: Fusarium chlamydosporum, chitinase, purification, Puccinia arachidis, uredospores.


1981 ◽  
Vol 193 (1) ◽  
pp. 187-192 ◽  
Author(s):  
H Nagase ◽  
A J Barrett

A simple method for isolation of kallikrein from human plasma is described. Before activation of the enzyme with acetone, the plasma was treated with 0.2 M-methylamine at pH 8.2 to inactivate alpha 2-macroglobulin and thus prevent the irreversible binding of the active enzyme to the inhibitor. The enzyme was adsorbed on soya-bean trypsin inhibitor-Sepharose 4B and eluted with 5 mM-NaOH, pH 11.3. It was further purified by immunoadsorption of contaminating proteins, and gel chromatography on Ultrogel AcA 44. About 3 mg of kallikrein was obtained from 400 ml of plasma (35% yield). The purified enzyme was shown to be homogeneous by electrophoretic and immunological criteria. The specific activities against benzyloxycarbonylphenylalanylarginine methylcoumarylamide, prolylphenylalanylarginine methylcoumarylamide and tosylarginine methyl ester were higher than any previously reported. The purified enzyme was resolved into two forms of mol.wts. 88 000 and 86 000 in sodium dodecyl sulphate/polyacrylamide-gel electrophoresis without reduction. Each consisted of three chains linked by disulphide bonds, one containing the reactive serine residue (mol.wt. 36 000 or 34 000), and two additional chains (mol.wt. 28 000 and 22 000).


1977 ◽  
Vol 161 (3) ◽  
pp. 543-549 ◽  
Author(s):  
B Burchell

1. A stable, more highly purified, preparation of UDP-glucuronyltransferase was obtained than previously reported. 2. Enzyme activity towards o-aminophenyl and p-nitrophenyl was increased 43- and 46-fold respectively. 3. The final preparation contains only three staining polypeptide bands visible after sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. 4. The only known major accompanying protein appears to be epoxide hydratase. 5. The purified enzyme activity towards o-aminophenol can still be activated 3 fold by diethylnitrosamine. 6. On evidence from purification, o-aminophenol and p-nitrophenol appear to be glucuronidated by the same enzyme protein. The possible recognition of the UDP-glucuronyltransferase enzyme is discussed.


1980 ◽  
Vol 192 (2) ◽  
pp. 507-516 ◽  
Author(s):  
T J Hopkirk ◽  
D P Bloxham

Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of immunoprecipitates of liver cytosol with anti-(L-type pyruvate kinase) serum revealed proteins of mol.wt. 56 000 and 42 000 in addition to the heavy and light chains. The ratio of the 56 000 mol.wt. to the 42 000 mol.wt. protein increased under dietary conditions that resulted in an increase in the apparent specific activity of hepatic pyruvate kinase. The 42 000 mol.wt. protein was removed from immunoprecipitates if the liver cytosol was partially purified by pH precipitation and (NH4)2SO4 fractionation before addition of the antiserum. This technique may be used to analyse the formation of pure L-type pyruvate kinase in liver. By using H14CO3-labelling, the t1/2 of L-type pyruvate kinase was estimated as 75 +/- 1.7 h in post-weaned high-carbohydrate-diet-fed rats. Before weaning there was little immunoreactive pyruvate kinase in rat liver cytosol. Induction began between 6 and 24 h after weaning and reached a maximum value 120 h after weaning. When clearly enhanced total pyruvate kinase activity was first observed at 24 h post-weaning, the apparent specific activity of hepatic pyruvate kinase was considerably lower than the specific activity of the pure isolated enzyme. When the induction of L-type pyruvate kinase was monitored by the incorporation of L-[4,5-3H]leucine, the maximum rate of synthesis occurred 24–48 h after weaning. After this period synthesis declined, indicating a relatively slow turnover of the enzyme once the enzyme concentration was established in the liver.


1979 ◽  
Vol 182 (2) ◽  
pp. 317-327 ◽  
Author(s):  
R N Sharma ◽  
R G Cameron ◽  
E Farber ◽  
M J Griffin ◽  
J G Joly ◽  
...  

Induction of hepatic microsomal mono-oxygenase species after administration of various xenobiotics is a well-documented phenomenon. To examine the number and specific species of rat liver microsomal membrane polypeptides involved in such responses, we have used sodium dodecyl sulphate/polyacrylamide-gel electrophoresis to analyse microsomal fractions from animals treated with a number of important xenobiotics. The following are the principal points to have emerged from this study. 1. A minimum of twelve electrophoretically distinct patterns of induction of haemopolypeptides and other polypeptides could be distinguished after administration, either singly or in certain combinations, of phenobarbital, 3-methylcholanthrene, polychlorinated biphenyls, 2-acetylaminofluorene, safrole (or isosafrole), pregnenolone-16 alpha-carbonitrile and ethanol. The patterns consisted of various permutations of the amounts of eight polypeptides of 47000-56000 mol.wt., of which at least three were haemopolypeptides. The possible identities of these polypeptides, which included species of cytochrome P-450, cytochrome P-448 and epoxide hydratase, are discussed. 2. Agents (3-methylcholanthrene, benzo[a]-pyrene, polychlorinated biphenyls, 2,3,7,8-tetrachlorodibenzo-p-dioxin and beta-naphthoflavone) that result in the induction of cytochrome P-448 caused a marked increase in two polypeptides of 54000 and 56000 mol.wt., whereas safrole and isosafrole induced only the former polypeptide. 3. Administration of 2-acetylaminofluorene resulted in the induction of two polypeptides; evidence is presented that suggests that one of these is a species of epoxide hydratase [cf. Levin, Lu, Thomas, Ryan, Kizer & Griffin (1978) Proc. Natl. Acad. Sci. U.S.A. 75, 3240-3243] ANd that the other may be a novel haemopolypeptide. 4. The overall results emphasize the complexity of the responses exhibited by rat liver microsomal fractions to the administration of xenobiotics.


1991 ◽  
Vol 65 (02) ◽  
pp. 169-173 ◽  
Author(s):  
Walter A Wuillemin ◽  
Miha Furlan ◽  
Isabella Huber ◽  
Bernhard Lämmle

SummaryThe specific clot promoting activity of factor XII (F XII) in plasma samples from 50 healthy adults was between 30 and 48 U/ mg, whereas the specific activity of purified F XII ranged from 55 to 66 U/mg. This difference was neither due to partial proteolytic activation during purification of F XII nor to the influence of plasma protease inhibitors. Purified F XII showed normal size and charge, as demonstrated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and isoelectric focusing, respectively. The increase of the specific F XII activity during the purification process mainly occurred after anion exchange chromatography on DEAE-Sephadex and after the final gel filtration step. Upon dextran sulfate activation, proteolytic cleavage of F XII and generation of kallikrein-like amidolytic activity was faster in F XII deficient plasma containing purified F XII than in F XII deficient plasma containing a corresponding amount of pooled normal plasma (NHP). The binding to kaolin was similar for both, purified F XII and plasma F XII.In conclusion, purification alters the properties of F XII in an unknown way, resulting in an increased specific clot promoting activity.


Sign in / Sign up

Export Citation Format

Share Document