Caractéristiques fonctionnelles des activités peroxydasiques des feuilles et cals d'une plante à métabolisme acide crassulacéen, Pedilanthus tithymaloides variegatus, Euphorbiaceae

1984 ◽  
Vol 62 (9) ◽  
pp. 901-907 ◽  
Author(s):  
Pierre Bricage

Peroxidases (donor:hydrogen-peroxide oxidoreductase; EC 1.11.1.7) from leaf tissues and calli were extracted and compared in terms of their specific activities at different pH and temperatures, their isoenzyme patterns and physicochemical properties. Three groups of enzyme activities were detected and their purification was performed by conventional methods (ammonium sulfate fractionation, ion-exchange chromatography, gel filtration, affinity chromatography).

Author(s):  
Angela Boxi ◽  
Isha Parikh ◽  
Radhika B S ◽  
Shryli K S

The present review is based on papers published between 1990 and 2020 and gives Comparative information about the most common protein purification techniques Gel-Filtration, Chromatography, Ion-Exchange Chromatography, Electrophoresis, Affinity Chromatography, and Dialysis, High-Pressure Liquid Chromatography. and their applications.


1982 ◽  
Vol 49 (3) ◽  
pp. 347-360 ◽  
Author(s):  
Joyce Toothill

SUMMARYSalivary and pancreatic lipases of the pre-ruminant calf have been studied using ion-exchange chromatography and gel filtration. In addition, pancreatic lipase has been fractionated using concanavalin A-affinity chromatography. The effects of 5,5′-dithiobis(2-nitrobenzoic acid), organic solvents and trypsin on pancreatic lipase have also been investigated. The effect of taurodeoxycholate on the lipolytic activity of the 2 lipases has been compared. Salivary lipase behaved as a single enzyme on ion-exchange chromatography, and gel filtration gave a mol. wt value of 52000 for the enzyme. Although pancreatic lipase appeared to be a single enzyme on gel filtration, with a mol. wt of almost 80000, the lipase was shown by ion-exchange and affinity chromatography to consist of at least 2 enzymes of mol. wts 72000 and 60000, and did not require colipase for maximum activity in the presence of high concentrations of bile salts. Colipase-dependent lipase, mol. wt about 45000, and probably amounting to not more than 10% of the total activity, was also present. This was the predominant form only after large losses in total lipolytic activity had occurred, as after treatment with a mixture of ether, ethanol and deoxycholate, or prolonged action of trypsin. When the concentration of taurodeoxycholate was increased from zero to 1 mM in a tributyrin substrate, the lipolytic activites of calf salivary and pancreatic lipases, and pig pancreatic lipase, increased. At a concentration of 4 mM-taurodeoxycholate, calf salivary lipase activity was higher, that of calf pancreatic lipase slightly lower and pig pancreatic lipase activity markedly lower.


Author(s):  
Barry Starcher ◽  
Marti Scott

The present study was designed to re-evaluate the radioimmunoassay for desmosine in urine, which is currently used as a measure of elastin metabolism. Using ion exchange chromatography, gel filtration and affinity chromatography it was shown that at least five other compounds in hydrolysates of human urine competed for desmosine in the RIA. Fractionating the urine prior to hydrolysis with acetone removed one of the major contaminants. The other contaminants could subsequently be removed by extracting the urine hydrolysate with a mixture of chloroform/ethanol (60:40). Samples from nine normal adult urines showed that an average of 45% of the RIA competing material in unfractionated urine was not desmosine. The final extracted residue retained all of the desmosine and only 16% of the original solids. The average adult urine contains approximately 50 pmol desmosine/mg creatinine, reflecting a daily turnover of between 3 and 4 mg of elastin per day.


1973 ◽  
Vol 30 (02) ◽  
pp. 414-424 ◽  
Author(s):  
Ulla Hedner

SummaryA procedure is described for partial purification of an inhibitor of the activation of plasminogen by urokinase and streptokinase. The method involves specific adsorption of contammants, ion-exchange chromatography on DEAE-Sephadex, gel filtration on Sephadex G-200 and preparative electrophoresis. The inhibitor fraction contained no antiplasmin, no plasminogen, no α1-antitrypsin, no antithrombin-III and was shown not to be α2 M or inter-α-inhibitor. It contained traces of prothrombin and cerulo-plasmin. An antiserum against the inhibitor fraction capable of neutralising the inhibitor in serum was raised in rabbits.


1990 ◽  
Vol 36 (11) ◽  
pp. 1906-1910 ◽  
Author(s):  
J Osada ◽  
T Gea ◽  
C Sanz ◽  
I Millan ◽  
J Botella

Abstract A group of substances of molecular masses between 300 and 1500 Da have been found to be toxic metabolites in patients with uremia. We determined the concentration in serum of these molecules in the following groups of patients: two hemodialyzed groups (one with cuprophane and the other with polyacrylonitrile dialyzers), one group treated with continuous ambulatory peritoneal dialysis, one group of nondialyzed azotemic patients, and one control group of healthy persons. Ultrafiltrates of the subjects' sera were fractionated on Sephadex G-15 followed by ion-exchange chromatography. Eluates were monitored by absorbance at 254 and 206 nm. Partially characterized peaks P1 and P2, obtained by gel filtration, correlated with the concentration of creatinine in serum; their concentrations were significantly (P less than 0.01) larger in hemodialyzed groups than in peritoneal dialyzed or in nondialyzed azotemic patients. After ion-exchange chromatography, two peaks (P'5 and P'6) correlated with serum creatinine and also were larger in hemodialyzed patients than in the other groups. Apparently, adequate discrimination is obtained by gel-filtration analysis and further analysis by ion-exchange chromatography does not provide additional information in most of the affected patients.


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.


OALib ◽  
2014 ◽  
Vol 01 (06) ◽  
pp. 1-5
Author(s):  
Mrigendra Rajput ◽  
Shimaa M. G. Mansour ◽  
Lyle J. Braun ◽  
Mahmoud Darweesh ◽  
Neelu Thakur ◽  
...  

1986 ◽  
Vol 233 (3) ◽  
pp. 885-891 ◽  
Author(s):  
J J F Sarkis ◽  
J A Guimarães ◽  
J M C Ribeiro

The salivary apyrase activity of the blood-sucking bug Rhodnius prolixus was found to reside in a true apyrase (ATP diphosphohydrolase, EC 3.6.1.5) enzyme. The crude saliva was devoid of 5′-nucleotidase, inorganic pyrophosphatase, phosphatase and adenylate kinase activities. ATP hydrolysis proceeded directly to AMP and Pi without significant accumulation of ADP. Km values for ATP and ADP hydrolysis were 229 and 291 microM respectively. Ki values for ATP and ADP inhibition of ADP and ATP hydrolysis were not different from the Km values, and these experiments indicated competitive inhibition. Activities were purified 126-fold by combined gel filtration and ion-exchange chromatography procedures with a yield of 63%. The purified enzyme displayed specific activities of 580 and 335 mumol of Pi released/min per mg of protein for ATP and ADP hydrolysis respectively. The action of the purified enzyme on several phosphate esters indicates that Rhodnius apyrase is a non-specific nucleosidetriphosphate diphosphohydrolase.


1973 ◽  
Vol 58 (3) ◽  
pp. 405-419 ◽  
Author(s):  
M. JOAN REED ◽  
S. R. STITCH

SUMMARY The uptake of 65Zn and [1,2-3H]testosterone by minced tissue of human benign hypertrophic prostates and the subcellular distribution of radioactivity were examined. The nature of steroid and 65Zn binding by the cytosol (105000 g supernatant) fraction was investigated by gel filtration, ion-exchange chromatography and electrophoresis. It was found that steroid binding after incubation at 4°C was specific. One or two regions of steroid binding were observed after gel filtration of the cytosol using Sephadex G-200, depending upon incubation conditions. Binding of 65Zn was found in the low molecular weight peak after G-200 gel filtration. Equimolar CdCl2 and 65ZnCl2 were incubated with [1,2-3H]testosterone and minced tissue and the cytosol was subjected to gel filtration. Compared with control values, without CdCl2, reduction of 65Zn binding by about 50% occurred, while binding of 3H-labelled steroid was unaffected. Electrophoresis and ion-exchange chromatography showed that 65Zn and 3H-labelled steroid were bound to different proteins. A sample of the zinc-binding protein was prepared by ion-exchange chromatography and the homogeneity was checked by electrophoresis.


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