Further purification and properties of rat uterine peroxidase

1981 ◽  
Vol 59 (11-12) ◽  
pp. 916-920 ◽  
Author(s):  
Hugh S. Keeping ◽  
Shioko Kimura ◽  
Jane Lovsted ◽  
Peter H. Jellinck

Peroxidase was purified 3700-fold from homogenates of estradiol-treated rat uteri by affinity chromatography on concanavalin A (ConA) – Sepharose followed by gel filtration on Bio-Gel P-150 with high recovery of enzyme. A single protein (molecular weight (MW) 45 000) staining for heme was shown by sodium dodecyl sulfate – polyacrylamide gel electrophoresis to be present in the peak fractions of enzymic activity eluted from the ConA–Sepharose column. This protein had the same mobility as bovine lactoperoxidase (MW 78 000) in a cationic gel electrophoretic system under nondenaturing conditions. Peroxidase activity in a NaCl extract of the uterus was lower than that in a CaCl2 extract but was unaffected by prolonged storage at −20 °C. In contrast, the CaCl2-extracted enzyme lost much, of its activity under these conditions by a process which could be prevented by the addition of glycerol. The sulfhydryl reagent, N-ethylmaleimide, which caused a marked increase in the activity of uterine peroxidase, provided only partial protection against inactivation during storage of CaCl2 extracts of this enzyme at low temperature.

1982 ◽  
Vol 207 (1) ◽  
pp. 133-138 ◽  
Author(s):  
M G Battelli ◽  
E Lorenzoni

A new GSSG-dependent thiol:disulphide oxidoreductase was extensively purified from rat liver cytosol. The enzymic protein shows molecular weight 40 000 as determined by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, and 43 000 as determined by thin-layer gel filtration on Bio-Gel P-100. The pI is 8.1. This enzyme converts rat liver xanthine dehydrogenase into an oxidase, in the presence of oxidized glutathione. Other disulphide compounds are either inactive or far less active than oxidized glutathione in the enzymic oxidation of rat liver xanthine dehydrogenase. The enzyme also catalyses the reduction of the disulphide bond of ricin and acts as a thioltransferase and as a GSH:insulin transhydrogenase. The enzymic activity was measured in various organs of newborn and adult rats.


1980 ◽  
Vol 187 (1) ◽  
pp. 123-129 ◽  
Author(s):  
J T Powell

Lung is one of the organs of the rat with a particular abundance of haemagglutinating activity that is inhibited by beta-galactosides. This lectin activity can be attributed to a single protein that has been purified from rat lung; a similar protein has been purified from human lung. The molecular weights and subunit structures were estimated from gel filtration and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis; the human lung lectin appeared to be composed to two identical subunits, mol.wt. 14500, whereas rat lung lectin was observed as both a dimer and a tetramer of one subunit type, mol.wt. 13500. Both lectins bind to disaccharides or oligosaccharides with terminal beta-linked galactose residues. The carbohydrate moiety may be free [lactose or D-galactopyranosyl-beta-(1 leads to 4)-thiogalactopyranoside], protein-bound (asialofetuin) or lipid-bound (cerebrosides). The molecular properties of the beta-galactoside-binding proteins of rat lung and human lung are closely similar to those of embryonic chick muscle lectin [Nowak, Kobiler, Roel & Barondes (1977) Proc. Natl. Acad. Sci. U.S.A. 73, 1383–1387] and calf heart lectin [De Waard, Hickman & Kornfeld (1976) J. Biol. Chem. 251, 7581–7587].


1976 ◽  
Vol 153 (2) ◽  
pp. 409-414 ◽  
Author(s):  
G S Bailey ◽  
R A Shipolini

A kininogenin (EC 3.4.21.8) was purified from the venom of Vipera ammodytes ammodytes (European sand viper) by a combination of gel filtration and ion-exchange chromatography. The enzyme is approximately six times more active than bovine trypsin in its ability to release vasoactive peptides from a plasma precursor. The kininogenin is a glycoprotein containing 18-20% by weight of carbohydrate. It showed a mol. wt. of 40500 on gel filtration. Gel electrophoresis of the reduced sample in the presence of sodium dodecyl sulphate and 2-mercaptoethanol revealed the presence of two major components of mol.wt. 34300 and 31300. The heterogeneity, which was also observed on disc electrophoresis, was removed by incubation with neuraminidase. After incubation with neuraminidase the kininogenin retained full enzymic activity and possessed an isoelectric point of pH7.2. The carbohydrate content has been decreased to 10% by weight, and the single component seen on electrophoresis in the presence of sodium dodecyl sulphate and 2-mercaptoethanol corresponded to a mol.wt. of 29500.


1983 ◽  
Vol 29 (11) ◽  
pp. 1526-1531 ◽  
Author(s):  
Susan E. Jensen ◽  
Donald W. S. Westlake ◽  
Saul Wolfe

Epimerase activity, which converts isopenicillin N to penicillin N, has been partially purified from cell-free extracts of Streptomyces clavuligerus. No stimulating cofactors of this activity were found, and neither EDTA nor anaerobic incubation caused significant inhibition of activity. Although pyridoxal phosphate did not stimulate epimerase activity, the presence of this cofactor was necessary for the stabilization of enzymic activity during the purification process. Epimerase activity was purified 35.5-fold by a combination of salt precipitation, gel filtration, and ion exchange chromatography. Gel filtration indicated that the epimerase has a molecular weight of 60 000 and sodium dodecyl sulphate – polyacrylamide gel electrophoresis of the 35.5-fold purified epimerase showed a major protein band running near that location. Pyridoxal phosphate antagonists did not uniformly inhibit epimerase activity, but the inhibitory effect of hydroxylamine could be partially reversed by pyridoxal phosphate.


1984 ◽  
Vol 224 (1) ◽  
pp. 171-179 ◽  
Author(s):  
I R Cottingham ◽  
A L Moore

The external NADH dehydrogenase has been purified from Arum maculatum (cuckoo-pint) mitochondria by phosphate washing, extraction with deoxycholate, ion-exchange and gel-filtration chromatography. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis shows, when the gel is silver-stained, that the purified enzyme contains two major bands of Mr 78 000 and 65 000 and a minor one of Mr about 76 000. It is not possible at present to determine which of these, or which combination, constitutes the dehydrogenase. The enzyme contains non-covalently bound FAD and a small amount of FMN. Since the conditions of purification lead to considerable loss of flavin and possibly iron-sulphur centres, it is not possible to decide with certainty whether the enzyme is a flavo- or ferroflavo-protein. The enzyme has been distinguished from the other NADH dehydrogenases on the basis of its substrate specificity, its capability of reducing electron acceptors such as ubiquinone-1 and 2,6-dichlorophenol-indophenol and its sensitivity towards Ca2+, EGTA and dicoumarol.


1975 ◽  
Vol 151 (2) ◽  
pp. 263-270 ◽  
Author(s):  
S A Betts ◽  
R J Mayer

1. 6-Phosphogluconate dehydrogenase from rabbit mammary gland was purified to homogeneity by the criterion of polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. The molecular weight of the subunit is 52 000. The enzyme was purified 150-fold with a final specific activity of 20 mumol of NADP+ reduced/min per mg of protein and overall yield of 3%. The molecular weight of the native enzyme is estimated to be 104 000 from gel-filtration studies. The final purification step was carried out by affinity chromatography with NADP+-Sepharose. 2. The Km values for 6-phosphogluconate and NADP+ are approx. 54 muM and 23 muM respectively. 3. Citrate and pyrophosphate are competitive inhibitors of the enzyme with respect to both 6-phosphogluconate and NADP+. 4. MgCl2 affects the apparent Km for NADP+ at saturating concentrations of 6-phosphogluconate.


1978 ◽  
Vol 56 (2) ◽  
pp. 159-165 ◽  
Author(s):  
J. R. A. Leushner ◽  
J. Pasternak

Prolyl hydroxylase was isolated from the free-living nematode Panagrellus silusiae by ammonium sulfate precipitation and calcium phosphate gel ion exchange from Triton X-100 treated homogenates. The enzyme preparation was highly purified but not to homogeneity as judged by agarose gel filtration and sodium dodecyl sulfate (SDS) – polyacrylamide gel electrophoresis. Gel filtration indicated that the molecular weight of the enzyme approximated 285 000. Analysis by SDS–acrylamide electrophoresis revealed subunits of ~67 000. Complete enzymic activity required α-ketoglutarate, Fe2+, ascorbate, catalase, atmospheric oxygen, and dithiothreitol. This activity was dramatically inhibited by α, α-dipyridyl, phenanthroline, and polyproline II. The purified enzyme preparation synthesized 50 to 100 μg hydroxyproline per milligram chick protocollagen per hour at 30 °C with an estimated Km for the substrate of 80 μg. Thus, a purified prolyl hydroxylase from a simple invertebrate possesses many of the properties of the prolyl hydroxylases of various vertebrates.


1985 ◽  
Vol 232 (1) ◽  
pp. 151-160 ◽  
Author(s):  
G J Hart ◽  
A R Battersby

Uroporphyrinogen III synthase (co-synthetase) purified from Euglena gracilis is a monomer of Mr 38 500 by gel-filtration studies and 31 000 by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The pI is apparently in the range 4.8-5.1. No evidence for any cofactors was found, and folate derivatives were shown to be absent; no metal ions appear to be present in the enzyme. The Km for hydroxymethylbilane is in the range 12-40 microM, and the product, uroporphyrinogen III, is an inhibitor. Modification studies suggest that arginine residues are essential for the activity of co-synthetase; lysine residues may also be essential, but histidine, cysteine and tyrosine residues are not.


Author(s):  
Masaki Ikemoto ◽  
Masayoshi Tabata ◽  
Takashi Murachi ◽  
Masayuki Totani

An efficient method for purification of human erythrocyte arginase was developed. This method included two new procedures, hydrophobic chromatography and immunoaffinity chromatography, and yielded 0·7 mg of homogeneous arginase protein from 2·1 L of haemolysate. The molecular weight of native arginase was estimated to be 105 000 by gel filtration on a Sephadex G-150 column, and that of its subunit 35 000 by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate. This indicates that the native enzyme is composed of three homologous subunits. Amino acid composition of human erythrocyte arginase was found to be very similar to that of liver arginase of several other mammals. After dialysis against distilled water, the purified arginase still retained its enzymatic activity which was decreased by EDTA and reversibly restored by Mn(II) ion. A specific polyclonal antibody for use in an immunoassay was also produced. This antibody revealed one single band on immunoelectrophoretic analysis of the acetone powder extract, suggesting absence of arginase isoenzymes in human erythrocytes.


1992 ◽  
Vol 38 (5) ◽  
pp. 436-442 ◽  
Author(s):  
Devyani Dey ◽  
Jyoti Hinge ◽  
Abhay Shendye ◽  
Mala Rao

An alkalophilic thermophilic Bacillus sp. (NCIM 59) isolated from soil produced two types of cellulase-free xylanase at pH 10 and 50 °C. The two enzymes (xylanase I and II) were purified to homogeneity by ethanol precipitation followed by Bio-Gel P-10 gel filtration and preparative polyacrylamide gel electrophoresis. The molecular weights of xylanase I and II were estimated to be 35 000 and 15 800, respectively, by sodium dodecyl sulfate gel electrophoresis. The enzymes exhibited immunological cross-reactivity and were glycoproteins. They had similar temperature (50–60 °C) and pH (6) optima. Both xylanases were stable at 50 °C at pH 7 for 4 days. However, xylanase I was comparatively more stable than xylanase II at 60 °C. The isoelectric points of xylanase I and II were 4 and 8, respectively. The apparent Km values, using xylan as substrate, were 1.58 and 3.5 mg/mL, and Vmax values were 0.0172 and 0.742 μmol∙min−1∙mg−1, respectively. Both xylanases were inhibited by N-bromosuccinimide, suggesting the involvement of tryptophan in the active site. The hydrolysis patterns demonstrated that the xylanases were endoenzymes. Xylanase I and II yielded mainly xylobiose, xylotriose, and higher xylooligosaccharides, with traces of xylose from xylan. Key words: cellulase-free xylanase, alkalophilic thermophilic Bacillus sp., enzyme purification, characterization.


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