scholarly journals Modification of erythrocyte membranes by a purified phosphatidylinositol-specific phospholipase C (Staphylococcus aureus)

1977 ◽  
Vol 162 (2) ◽  
pp. 235-240 ◽  
Author(s):  
M G Low ◽  
J B Finean
Keyword(s):  
Staphylococcus Aureus ◽  
Phospholipase C ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Phosphatidyl Inositol ◽  
Thiol Group ◽  
Erythrocyte Membranes ◽  
Haemolytic Activity

A phosphatidylinositol-specific phospholipase C from Staphylococcus aureus was purified by a three-step procedure. The specific activity of the purified enzyme was approx. 6000 times that of the culture supernatant, with an overall recovery of approx. 10%. Estimation of the molecular weight by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and by gel filtration gave values of 33000 and 20000 respectively. A thiol group appears to be necessary for the activity of the enzyme. The purified enzyme had no detectable delta-haemolytic activity and was unable to hydrolyse S. aureus phospholipids. Phosphatidyl-inositol in erythrocyte ‘ghosts’ was readily hydrolysed by the purified phospholipase C. However, in contrast with our previous preliminary observations, phosphatidylinositol in intact erythrocytes was not significantly hydrolysed. These results suggest that at least 75-80% of the phosphatidylinositol is located at the inner leaflet of the membrane.

scholarly journals Isolation, partial purification and characterization of phospholipase A2 from Naja Katiensis venom

2021 ◽  
Vol 13 (2) ◽  
pp. 107-112
Author(s):  
C.F. Okechukwu ◽  
P.L. Shamsudeen ◽  
R.K. Bala ◽  
B.G. Kurfi ◽  
A.M. Abdulazeez
Keyword(s):  
Ion Exchange ◽  
Phospholipase A2 ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Partial Purification ◽  
Crude Venom

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.

Phospholipase C (heat-labile hemolysin) of Pseudomonas aeruginosa: purification and preliminary characterization

1982 ◽  
Vol 152 (1) ◽  
pp. 239-245
Author(s):  
R M Berka ◽  
M L Vasil
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Phospholipase C ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Size Exclusion ◽  
Tetradecyltrimethylammonium Bromide ◽  
Heat Labile ◽  
Hydrophobic Moiety ◽  
Culture Supernatants

Phospholipase C (heat-labile hemolysin) was purified from Pseudomonas aeruginosa culture supernatants to near homogeneity by ammonium sulfate precipitation followed by a novel application of DEAE-Sephacel chromatography. Enzymatic activity remained associated with DEAE-Sephacel even in the presence of 1 M NaCl, but was eluted with a linear gradient of 0 to 5% tetradecyltrimethylammonium bromide. Elution from DEAE-Sephacel was also obtained with 2% lysophosphatidylcholine, and to a lesser extent with 2% phosphorylcholine, but not at all with choline. The enzyme was highly active toward phospholipids possessing substituted ammonium groups (e.g., phosphatidycholine, lysophosphatidylcholine, and sphingomyelin); however, it had little if any activity toward phospholipids lacking substituted ammonium groups (e.g., phosphatidylethanolamine, phosphatidylserine, and phosphaditylglycerol). Collectively, these data suggest that phospholipase C from P. aeruginosa exhibits high affinity for substituted ammonium groups, but requires an additional hydrophobic moiety for optimum binding. The specific activity of the purified enzyme preparation increased 1,900-fold compared with that of culture supernatants. The molecular weight of the phospholipase C was estimated to be 78,000 by both sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Sephacryl S-200 column chromatography and was 76,000 by high-performance size exclusion chromatography. The isoelectric point was 5.5. Amino acid analysis showed that phospholipase C was rich in glycine, serine, threonine, aspartyl, glutamyl, and aromatic amino acids, but was cystine free.

scholarly journals Molecular Characterization of a Recombinant Manganese Superoxide Dismutase fromLactococcus lactisM4

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Boon Hooi Tan ◽  
Thean Chor Leow ◽  
Hooi Ling Foo ◽  
Raha Abdul Rahim
Keyword(s):  
Superoxide Dismutase ◽  
Active Sites ◽  
Manganese Superoxide Dismutase ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Maximal Activity ◽  
Gel Filtration Chromatography ◽  
T7 Promoter

A superoxide dismutase (SOD) gene ofLactococcus lactisM4 was cloned and expressed in a prokaryotic system. Sequence analysis revealed an open reading frame of 621 bp which codes for 206 amino acid residues. Expression ofsodAunder T7 promoter exhibited a specific activity of 4967 U/mg when induced with 1 mM of isopropyl-β-D-thiogalactopyranoside. The recombinant SOD was purified to homogeneity by immobilised metal affinity chromatography and Superose 12 gel filtration chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and western blot analyses of the recombinant SOD detected a molecular mass of approximately 27 kDa. However, the SOD was in dimer form as revealed by gel filtration chromatography. The purified recombinant enzyme had a pI of 4.5 and exhibited maximal activity at 25°C and pH 7.2. It was stable up to 45°C. The insensitivity of this lactococcal SOD to cyanide and hydrogen peroxide established that it was a MnSOD. Although it has 98% homology to SOD ofL. lactisIL1403, this is the first elucidated structure of lactococcal SOD revealing active sites containing the catalytic manganese coordinated by four ligands (H-27, H-82, D-168, and H-172).

scholarly journals Purification, characterization and inhibition of human skin collagenase

1978 ◽  
Vol 169 (2) ◽  
pp. 265-276 ◽  
Author(s):  
David E. Woolley ◽  
Robert W. Glanville ◽  
Dennis R. Roberts ◽  
John M. Evanson
Keyword(s):  
Human Skin ◽  
Culture Medium ◽  
Serum Proteins ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Polyacrylamide Gel ◽  
Collagen Fibrils ◽  
Ph Optimum

1. The neutral collagenase released into the culture medium by explants of human skin tissue was purified by ultrafiltration and column chromatography. The final enzyme preparation had a specific activity against thermally reconstituted collagen fibrils of 32μg of collagen degraded/min per mg of enzyme protein, representing a 266-fold increase over that of the culture medium. Electrophoresis in polyacrylamide disc gels showed it to migrate as a single protein band from which enzyme activity could be eluted. Chromatographic and polyacrylamide-gel-elution experiments provided no evidence for the existence of more than one active collagenase. 2. The molecular weight of the enzyme estimated from gel filtration and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis was approx. 60000. The purified collagenase, having a pH optimum of 7.5–8.5, did not hydrolyse the synthetic collagen peptide 4-phenylazobenzyloxycarbonyl-Pro-Leu-Gly-Pro-d-Arg-OH and had no non-specific proteinase activity when examined against non-collagenous proteins. 3. It attacked undenatured collagen in solution at 25°C, producing the two characteristic products TCA(¾) and TCB(¼). Collagen types I, II and III were all cleaved in a similar manner by the enzyme at 25°C, but under similar conditions basement-membrane collagen appeared not to be susceptible to collagenase attack. At 37°C the enzyme attacked gelatin, producing initially three-quarter and one-quarter fragments of the α-chains, which were degraded further at a lower rate. As judged by the release of soluble hydroxyproline peptides and electron microscopy, the purified enzyme degraded insoluble collagen derived from human skin at 37°C, but at a rate much lower than that for reconstituted collagen fibrils. 4. Inhibition of the skin collagenase was obtained with EDTA, 1,10-phenanthroline, cysteine, dithiothreitol and sodium aurothiomaleate. Cartilage proteoglycans did not inhibit the enzyme. The serum proteins α2-macroglobulin and β1-anti-collagenase both inhibited the enzyme, but α1-anti-trypsin did not. 5. The physicochemical and enzymic properties of the skin enzyme are discussed in relation to those of other human collagenases.

scholarly journals Purification of the enzyme NADPH: protochlorophyllide oxidoreductase

1981 ◽  
Vol 195 (1) ◽  
pp. 83-92 ◽  
Author(s):  
N S Beer ◽  
W T Griffiths
Keyword(s):  
Specific Activity ◽  
Gradient Centrifugation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
High Specific Activity ◽  
Sucrose Density Gradient ◽  
Sucrose Density Gradient Centrifugation ◽  
Triton X ◽  
Etioplast Membranes

A procedure for the purification of the enzyme NADPH:protochlorophyllide oxidoreductase is described. This involves fractionation of sonicated oat etioplast membranes by discontinuous-sucrose-density-gradient centrifugation, which gives membranes in which the enzyme is present at a high specific activity. The enzyme is solubilized from the membranes with Triton X-100, followed by gel filtration of the extract; enzyme activity is eluted in fractions corresponding to a mol.wt of approx. 35000. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of the enzyme-containing fractions from gel filtration shows two peptides, of mol.wts. approx. 35000 and 37000.

Purification and preliminary characterization of 2-monoacylglycerol acyltransferase from rat intestinal villus cells

1985 ◽  
Vol 63 (5) ◽  
pp. 341-347 ◽  
Author(s):  
F. Manganaro ◽  
A. Kuksis
Keyword(s):  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Cell Protein ◽  
Racemic Mixture ◽  
Small Intestinal Mucosa ◽  
Small Intestinal ◽  
Monoacylglycerol Acyltransferase

We have purified the monoacylglycerol acyltransferase from rat small intestinal mucosa to homogeneity by a combination of hydrophobic absorption, guanidine dissociation, and gel filtration. The purified enzyme gives a single band of 37 000 daltons on sodium dodecyl sulphate – polyacrylamide gel electrophoresis. The enzyme has a specific activity of about 5900 nmol/mg per hour and represents 0.12% of total cell protein, corresponding to about a 600-fold purification. The enzyme does not acylate diacylglycerols to triacylglycerols, which is consistent with the separate physical existence of the mono- and di-acylglycerol acyltransferases. The enzyme acylates the 2-monoacylglycerols to yield an essentially racemic mixture of diacylglycerols. It does not acylate glycerol 3-phosphate.

Purification and Characterization of Kallikrein from Plasma of Patients with Acute Pancreatitis

1981 ◽  
Vol 60 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Naotika Toki ◽  
Hiroyuki Sumi ◽  
Sumiyoshi Takasugi
Keyword(s):  
Acute Pancreatitis ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Apparent Molecular Weight ◽  
Purification And Characterization ◽  
Α2 Macroglobulin ◽  
Sepharose 4B

1. A kallikrein-like enzyme in plasma of patients with acute pancreatitis was further purified by successive hydroxyapatite/cellulose and Sepharose-4B column chromatography. 2. By these procedures 0.26 mg of purified enzyme with a specific activity of 215 S-2266 chromozyme units/mg of protein was obtained from 10 ml of original plasma. 3. The purified material was homogeneous as ascertained by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and had an apparent molecular weight of 31 000 as measured by gel filtration on Sephadex G-200. 4. It was confirmed immunologically that this enzyme was pancreatic kallikrein, which is distinct from plasma kallikrein, and that it could combine with α2-macroglobulin only in the presence of trypsin.

scholarly journals O-Acetylserine Sulfhydrylase fromMethanosarcina thermophila

2000 ◽  
Vol 182 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Birthe Borup ◽  
James G. Ferry
Keyword(s):  
Specific Activity ◽  
Sequence Similarity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Substrate Inhibition ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Cysteine Biosynthesis ◽  
High Sequence Similarity ◽  
Methanosarcina Thermophila ◽  
Moderately Thermophilic

ABSTRACT Cysteine is the major source of fixed sulfur for the synthesis of sulfur-containing compounds in organisms of the Bacteriaand Eucarya domains. Though pathways for cysteine biosynthesis have been established for both of these domains, it is unknown how the Archaea fix sulfur or synthesize cysteine. None of the four archaeal genomes sequenced to date contain open reading frames with identities to eitherO-acetyl-l-serine sulfhydrylase (OASS) or homocysteine synthase, the only sulfur-fixing enzymes known in nature. We report the purification and characterization of OASS from acetate-grown Methanosarcina thermophila, a moderately thermophilic methanoarchaeon. The purified OASS contained pyridoxal 5′-phosphate and catalyzed the formation of l-cysteine and acetate from O-acetyl-l-serine and sulfide. The N-terminal amino acid sequence has high sequence similarity with other known OASS enzymes from the Eucarya andBacteria domains. The purified OASS had a specific activity of 129 μmol of cysteine/min/mg, with a Km of 500 ± 80 μM for sulfide, and exhibited positive cooperativity and substrate inhibition withO-acetyl-l-serine. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a single band at 36 kDa, and native gel filtration chromatography indicated a molecular mass of 93 kDa, suggesting that the purified OASS is either a homodimer or a homotrimer. The optimum temperature for activity was between 40 and 60°C, consistent with the optimum growth temperature for M. thermophila. The results of this study provide the first evidence for a sulfur-fixing enzyme in the Archaea domain. The results also provide the first biochemical evidence for an enzyme with the potential for involvement in cysteine biosynthesis in theArchaea.

scholarly journals New Exfoliative Toxin Produced by a Plasmid-Carrying Strain of Staphylococcus hyicus

1999 ◽  
Vol 67 (8) ◽  
pp. 4014-4018 ◽  
Author(s):  
Hisaaki Sato ◽  
Takao Watanabe ◽  
Yasuko Murata ◽  
Ayumi Ohtake ◽  
Mayumi Nakamura ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Staphylococcus Aureus ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
The Other ◽  
Exfoliative Toxin ◽  
Sds Page ◽  
Serotype B

ABSTRACT A new serotype of Staphylococcus hyicus exfoliative toxin (SHET), serotype B, was isolated from the culture filtrate of a plasmid-carrying strain of S. hyicus. The new SHET was purified by precipitation with 70% saturated ammonium sulfate, gel filtration on a Sephadex G-75 column, column chromatography on DEAE–Cellulofine A-500, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The new SHET caused exfoliation of the epidermis as determined by the so-called Nikolsky sign when inoculated into 1-day-old chickens. The new SHET was serologically different fromStaphylococcus aureus exfoliative toxins (ETs) (ETA, ETB, and ETC) and from the SHET from the plasmidless strain but showed the same molecular weight as the other serotypes of toxins on SDS-PAGE. It was thermolabile and lost its toxicity after being heated at 60°C for 30 min. We propose that the new SHET be designated SHETB and that the SHET produced by the plasmidless strain be designated SHETA.

scholarly journals Purification and properties of 6-phosphogluconate dehydrogenase from rabbit mammary gland

1975 ◽  
Vol 151 (2) ◽  
pp. 263-270 ◽  
Author(s):  
S A Betts ◽  
R J Mayer
Keyword(s):  
Molecular Weight ◽  
Mammary Gland ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Phosphogluconate Dehydrogenase ◽  
Purification And Properties ◽  
Competitive Inhibitors ◽  
Final Purification Step

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.

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