scholarly journals A method for the purification of milligram quantities of stable human phosphatidylcholine-cholesterol acyltransferase

1976 ◽  
Vol 155 (3) ◽  
pp. 583-588 ◽  
Author(s):  
K G Varma ◽  
L A Soloff
Keyword(s):  
Enzyme Activity ◽  
Acid Treatment ◽  
Sodium Phosphate ◽  
Cholesterol Acyltransferase ◽  
Deae Cellulose ◽  
Polyacrylamide Gel ◽  
Enzyme Protein ◽  
Faint Band ◽  
Slow Moving ◽  
Moving Band

A method for processing 3 litres of human plasma for the purification of phosphatidylcholine-cholesterol acyltransferase is described. The method involves (NH4)2SO4 fractionation, citric acid treatment, and DEAE-cellulose and hydroxyapatite chromatography. At this stage the enzyme preparation is purified approx. 8000-fold. This preparation appears to be free of lipoproteins as determined by immunoelectrophoresis against anti-human serum and is minimally contaminated with albumin (less than 30 mug/mg of enzyme protein) as determined by immunodiffusion. The activity of the enzyme was stable for 4 days, but most of its activity was lost after 20 days On electrophoresis on 5% polyacrylamide gel, a fast-moving band with enzyme activity and a slow-moving band with no enzyme activity was observed. A faint band of albumin was also present. Extracts of enzymically active bands cut from ten gels and then pooled and extracted with 0.15 M-NaC1/4mM-sodium phosphate, pH 7.0, showed a single band on re-electrophoresis on 5% polyacrylamide gel.

scholarly journals Studies on the purification of rat liver uridine diphosphate glucuronyltransferase

1977 ◽  
Vol 161 (3) ◽  
pp. 543-549 ◽  
Author(s):  
B Burchell
Keyword(s):  
Enzyme Activity ◽  
Rat Liver ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Uridine Diphosphate ◽  
Enzyme Protein ◽  
Epoxide Hydratase

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.

scholarly journals Fractionation and isolation of the multiple forms of prorennin (prochymosin)

1972 ◽  
Vol 129 (4) ◽  
pp. 841-846 ◽  
Author(s):  
N. Asato ◽  
A. G. Rand
Keyword(s):  
Gel Electrophoresis ◽  
Sodium Phosphate ◽  
Polyacrylamide Gel Electrophoresis ◽  
Deae Cellulose ◽  
Polyacrylamide Gel ◽  
Multiple Forms ◽  
Salting Out ◽  
Alum Treatment ◽  
Three Components

The heterogeneity of prorennin was studied by chromatography on DEAE-cellulose and microgranular DEAE-cellulose columns, as well as by polyacrylamide-gel electrophoresis. Prorennin prepared by alum treatment, salting-out and chromatography was resolved into three components by a compound gradient of sodium phosphate on microgranular DEAE-cellulose. Polyacrylamide-gel electrophoresis confirmed the chromatographic results, but crystalline rennin was shown to consist of four bands. When prorennin was isolated directly by chromatography, four zymogen components were resolved on microgranular DEAE-cellulose with a modified compound gradient of sodium phosphate. Polyacrylamide-gel electrophoresis confirmed the existence of four multiple forms of prorennin as well as homogeneity of the chromatographic fractions.

scholarly journals Induction of carnitine acetyltransferase by clofibrate in rat liver

1981 ◽  
Vol 194 (1) ◽  
pp. 249-255 ◽  
Author(s):  
B Mittal ◽  
C K R Kurup
Keyword(s):  
Protein Synthesis ◽  
Enzyme Activity ◽  
Rat Liver ◽  
Time Lag ◽  
Mitochondrial Protein ◽  
Carnitine Acetyltransferase ◽  
Enzyme Protein ◽  
General Protein Synthesis ◽  
Liver And Kidney ◽  
General Protein

Administration of the anti-hypercholesterolaemic drug clofibrate to the rat increases the activity of carnitine acetyltransferase (acetyl-CoA-carnitine O-acetyltransferase, EC 2.3.1.7) in liver and kidney. The drug-mediated increase in enzyme activity in hepatic mitochondria shows a time lag during which the activity increases in the microsomal and peroxisomal fractions. The enzyme induced in the particulate fractions is identical with one normally present in mitochondria. The increase in enzyme activity is prevented by inhibitors of RNA and general protein synthesis. Mitochondrial protein-synthetic machinery does not appear to be involved in the process. Immunoprecipitation shows increased concentration of the enzyme protein in hepatic mitochondria isolated from drug-treated animals. In these animals, the rate of synthesis of the enzyme is increased 7-fold.

scholarly journals Purification and subunit structure of argininosuccinate lyase from Chlamydomonas reinhardi

1977 ◽  
Vol 167 (1) ◽  
pp. 71-75 ◽  
Author(s):  
R F Matagne ◽  
J P Schlösser
Keyword(s):  
Enzyme Activity ◽  
Crude Extract ◽  
Enzyme Preparation ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Activity Analysis ◽  
Disc Electrophoresis ◽  
Subunit Structure ◽  
Argininosuccinate Lyase

Argininosuccinate lyase (EC 4.3.2.1) was purified by (NH4)2SO4 fractionation, chromatography on DEAE-cellulose and gel filtration on Sephadex G-200. The final enzyme preparation was purified 46-fold compared with the crude extract. Electrophoresis of this preparation revealed three bands, the major one having the enzyme activity. Analysis of the enzyme by gel filtration and by disc electrophoresis (in two different concentrations of acrylamide) gave mol.wts. of 200000 (+/- 15000) and 190000 (+/- 20000) respectively. Treatment with sodium dodecyl sulphate and mercaptoethanol dissociated the enzyme into subunits of mol.wt. 39000 (+/-2000). The results are indicative of the multimeric structure of the enzyme, which is composed of five (perhaps four or six) identical subunits.

scholarly journals Analysis of the forms of acetylcholinesterase from adult mouse brain

1975 ◽  
Vol 147 (2) ◽  
pp. 205-214 ◽  
Author(s):  
E D Adamson ◽  
S E Ayers ◽  
Z A Deussen ◽  
C F Graham
Keyword(s):  
Enzyme Activity ◽  
Mouse Brain ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Acetylcholinesterase Activity ◽  
Total Activity ◽  
Polyacrylamide Gel ◽  
Soluble Extract ◽  
Molecular Sizes

The solubilization of 80% of the acetylcholinesterase activity of mouse brain was performed by repeated 2h incubations of homogenates at 37 degrees C in an aqueous medium. Analysis of the soluble extract by gel filtration on Sephadex G-200 showed that up to 80% of the enzyme activity was eluted in a peak which was estimated to consist of molecules of about 74000mol.wt. This peak was called the monomer form of the enzyme. After 3 days at 4 degrees C, the soluble extract was re-analysed and was eluted from the column in four peaks of about 74000, 155000, 360000 and 720000 mol.wt. Since the total activity of the enzyme in these peaks was the same as that in the predominantly monomer elution profile of fresh enzyme, we concluded that the monomer had aggregated, possibly into dimers, tetramers and octomers. Extracts of the enzyme were analysed by polyacrylamide-gel electrophoresis and the resulting multiple bands of enzyme activity on gels were shown to separate according to their molecular sizes, that is by molecular sieving. All these forms had similar susceptibilities to the inhibitors eserine, tetra-isopropyl pyrophosphoramide and compound BW 284c51 [1,5-bis-(4-allyldimethylammoniumphenyl)pentan-3-one dibromide]. Thus the forms of the enzyme in mouse brain which can be detected by gel filtration and polyacrylamide-gel electrophoresis may all be related to a single low-molecular-weight form which aggregates during storage. This supports similar suggestions made for the enzyme in other locations.

Extracellular nuclease produced by a marine bacterium. II. Purification and properties of extracellular nuclease from a marine Vibrio sp.

1976 ◽  
Vol 22 (10) ◽  
pp. 1443-1452 ◽  
Author(s):  
M. Maeda ◽  
N. Taga
Keyword(s):  
Enzyme Activity ◽  
Deae Cellulose ◽  
Strong Stability ◽  
Rnase Activity ◽  
Salting Out ◽  
Deae Cellulose Column ◽  
Marine Vibrio ◽  
Extracellular Nuclease ◽  
Marine Vibrio Sp ◽  
Cellulose Column

Extracellular nuclease produced by a marine Vibrio sp., strain No. 2, was purified by salting out with ammonium sulfate and by chromatography on a DEAE-cellulose column and twice on a Sephadex G-200 column. The nuclease was eluted as a single peak in which the deoxyribonuclease (DNase) activity and ribonuclease (RNase) activity appeared together. Polyacrylamide disc gel electrophoresis showed a single band of stained protein which had both DNase and RNase activity. The molecular weight of the enzyme was estimated to be 100 000 daltons. When using partially purified enzyme from the DEAE-cellulose column, the optimum pH for activity was 8.0, and the enzyme was activated strongly by 0.05 M Mg2+ ion and stabilized by 0.01 M Ca2+ ion. These concentrations of Mg2+ and Ca2+ ions are similar to those of the two cations in seawater. Indeed, the enzyme revealed high activity and strong stability when kept in seawater. The presence of particulate matter, such as cellulose powder, chitin powder, Hyflosupercel, Kaolin, and marine mud increased the stability of the enzyme. When the hydrostatic pressure was increased from 1 to 1000 atmospheres, the decrements of the enzyme activity were more pronounced at 30 and 40 °C than at 25 or 50 °C. The enzyme activity was restored after decompression to 1 atm at 30 °C.

Screening for Highly Active Plasmid Promoters via Fusion to β-Galactosidase Gene

1982 ◽  
Vol 37 (5-6) ◽  
pp. 441-444
Author(s):  
Arie Rosner ◽  
Marian Gorecki ◽  
Haim Aviv
Keyword(s):  
Enzyme Activity ◽  
Enzyme Activities ◽  
Polyacrylamide Gel ◽  
Highly Active ◽  
Red Color ◽  
Wide Range ◽  
The Future ◽  
Active Promoter

Abstract A plasmid containing promoter-deleted inactive β-galactosidase gene [1] was used to select promoters of the pEP121 plasmid [2]. Colonies of cells harboring reactivated β-galactosidase gene were identified by their red color on McConkey plates. The quantitative amounts of β-galactosidase produced in each clone were estimated by assaying enzyme activity and by measuring the specific β-galactosidase protein following fractionation of total cells′ proteins on polyacrylamide gel. A wide range of enzyme activities was observed. The most active promoter isolated was shown to promote β-galactosidase production more efficiently, compared with the original β-galactosidase promoter, amounting to 20% of all cell proteins. Such highly active promoters may be utilized in the future, to promote expression of cloned genes in bacteria.

scholarly journals PURIFICATION AND PHYSICAL PROPERTIES OF GROUP C STREPTOCOCCAL PHAGE-ASSOCIATED LYSIN

1971 ◽  
Vol 133 (5) ◽  
pp. 1105-1117 ◽  
Author(s):  
Vincent A. Fischetti ◽  
Emil C. Gotschlich ◽  
Alan W. Bernheimer
Keyword(s):  
Molecular Weight ◽  
Enzyme Activity ◽  
Physical Properties ◽  
Total Protein ◽  
Sedimentation Coefficient ◽  
Polyacrylamide Gel ◽  
Single Band ◽  
Purification Procedure ◽  
Sh Group ◽  
Stokes Radius

A purification procedure for the Group C phage-associated lysin is described utilizing tetrathionate to protect the enzyme's -SH group(s) from thiol-inactivating agents. A 652-fold purification has been accomplished yielding a solution in which the enzyme activity corresponds to essentially a single band on polyacrylamide gel which accounts for 70% of the total protein in the preparation. A molecular weight of 101,000 and frictional ratio of 1.526 was determined for the lysin utilizing experimentally determined values for its Stokes radius and sedimentation coefficient.

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