Isolation and characterization of ferritin from the liver of the rainbow trout (Salmo gairdneri R.)

1991 ◽  
Vol 69 (10-11) ◽  
pp. 735-741 ◽  
Author(s):  
J. L. Miguel ◽  
M. I. Pablos ◽  
M. T. Agapito ◽  
J. M. Recio

A method for the purification of ferritin from rainbow trout liver by heat extraction and gel filtration is described. The number of iron atoms varied from 500 to 2000 in purified ferritin. The neutral sugar composition detected was 86 mol of glucose, 24 mol of fucose, 12 mol of galactose, and 8 mol of mannose per mol of ferritin and apoferritin. Release of iron was achieved using low molecular weight chelating agents. The order of effectiveness of chelators was nitrilotriacetate > EDTA > citrate. Removal of the iron does not imply reduction of Fe3+. The rate of release of iron increased with decreasing pH. The slowest release was at pH 7.5. The endogenous chelator is not only sulphydrylic but seems to include carbohydrates that participate in the binding of Fe2+. Trout ferritin exhibits heterogeneity upon isoelectric focusing; four isoferritins with pI values of 4.5 to 4.85 were detected. This heterogeneity represents polymorphic, not polymer, forms. The amino acid composition differs from that of ferritins from other species. High concentrations of glutamic and aspartic acids, alanine, leucine, glycine, and lysine were detected along with low concentrations of methionine and cysteine.Key words: ferritin, isoferritin, rainbow trout.

1979 ◽  
Vol 177 (1) ◽  
pp. 9-19 ◽  
Author(s):  
Gabriel M. Umezurike

1. Filtrates from cultures of different ages of Botryodiplodia theobromae Pat. were fractionated by gel filtration, ion-exchange chromatography and polyacrylamide-gel electrophoresis. 2. Five cellulases (C1, C2, C3, C4 and C5) were found, and their molecular weights, estimated by gel filtration, were 46000–48000 (C1), 30000–35000 (C2), 15000–18000 (C3), 10000–11000 (C4) and 4800–5500 (C5). 3. Cellulase C5 was absent from old culture filtrates. 4. Cellulase C1 had little or no activity on CM-cellulose (viscometric assay), but degraded cotton flock and Whatman cellulose powder to give cellobiose only. 5. The other components (C2–C5) produced cellobiose and smaller amounts of glucose and cellotriose from cellulosic substrates and were more active in lowering the viscosity of CM-cellulose. 6. The ratio of activities assayed by viscometry and by the release of reducing sugars from CM-cellulose increased with decrease in the molecular weights of cellulases C2–C5. 7. Cellobiose inhibited the activities of the cellulases, but glucose stimulated at low concentrations although it inhibited at high concentrations. 8. A high-molecular-weight β-glucosidase (component B1, mol.wt. 350000–380000) predominated in filtrates from young cultures, but a low-molecular-weight enzyme (B4, mol.wt. 45000–47000) predominated in older filtrates. 9. Intermediate molecular species of β-glucosidase (B2, mol.wt. 170000–180000; B3, mol.wt. 83000–87000) were also found. 10. Cellulases C2–C5 acted in synergism with C1, particularly in the presence of β-glucosidase.


1983 ◽  
Vol 3 (12) ◽  
pp. 2166-2171
Author(s):  
B Gilfix ◽  
J Rogers ◽  
B D Sanwal

Mutants resistant to the lethal action of the lectins phytohemagglutinin A (PHA) and wheat germ agglutinin (WGA) have been made in a line of differentiating rat skeletal myoblasts. The WGA mutants are of two types, WGArII, resistant to low concentrations of the lectin, and WGArI, resistant to high concentrations of the lectin. WGArII and PHAr mutants are unable to differentiate, whereas WGArI mutants differentiate normally. WGArII mutants are not impaired in the binding of wheat germ agglutinin, but WGArI mutants bind the lectin only to the extent of about 50% of the wild-type values. All of the mutants are cross-resistant to lectins other than those used in their selection.


1984 ◽  
Vol 62 (8) ◽  
pp. 1495-1501 ◽  
Author(s):  
J. G. Eales ◽  
Shirley Shostak ◽  
Catherine G. Flood

The effects of the thiols DTT (dithiothreitol) and GSH (reduced glutathione) on hepatic in vitro and in vivo T4 (L-thyroxine) deiodination by rainbow trout held at 11 °C were studied. Hepatic deiodination increased progressively over the DTT range of 0.02–20 mM. GSH was less potent than DTT at low concentrations and strongly inhibited deiodination at high concentrations (> 1 mM). Hepatic deiodination was not increased by 1 mM NADPH or anaerobic conditions and was enhanced and not inhibited by the GSH inhibitor, diamide (2.5 mM), indicating that the low T4 deiodination in the absence of DTT is not due to endogenous GSH deficiency. Intraperitoneally injected GSH consistently increased plasma levels of 125I and [125I]-3,5,3′-triiodo-L-thyronine (T3) in fed or starved [125I]T4-injected trout, suggesting a GSH stimulation of extrahepatic T4 deiodination. However, injected GSH did not elevate plasma T3 concentrations. This was probably due to a demonstrated GSH stimulation of plasma T4 and T3 clearance. Force-fed GSH did not increase [125I]T4 deiodination. It is concluded that exogenous thiols can enhance T4 deiodination both in vitro and in vivo. However, availability of neither endogenous nor dietary GSH appears to regulate T4 deiodination under physiological conditions, including altered nutritional state.


1983 ◽  
Vol 3 (12) ◽  
pp. 2166-2171 ◽  
Author(s):  
B Gilfix ◽  
J Rogers ◽  
B D Sanwal

Mutants resistant to the lethal action of the lectins phytohemagglutinin A (PHA) and wheat germ agglutinin (WGA) have been made in a line of differentiating rat skeletal myoblasts. The WGA mutants are of two types, WGArII, resistant to low concentrations of the lectin, and WGArI, resistant to high concentrations of the lectin. WGArII and PHAr mutants are unable to differentiate, whereas WGArI mutants differentiate normally. WGArII mutants are not impaired in the binding of wheat germ agglutinin, but WGArI mutants bind the lectin only to the extent of about 50% of the wild-type values. All of the mutants are cross-resistant to lectins other than those used in their selection.


1971 ◽  
Vol 26 (01) ◽  
pp. 177-191 ◽  
Author(s):  
I Holmsen ◽  
H Holmsen

SummaryPlasma contains enzymes capable of dephosphorylating ADP, ATP and AMP (adenosine di-, tri- and monophosphate). In platelet-rich plasma these enzymes are important for the regulation of the levels of (platelet-aggregating) ADP and (aggregation-inhibitory) adenosine.Plasma ADPase and ATPase were studied at 1 (µM substrate concentration using an isotope technique. Both enzymes were precipitated from plasma at 45-65% saturation with (NH4)2S04 and emerged together by gel filtration on Sephadex G-200 and from DEAE-Sephadex (0.12-0.20 M Cl-, pH 8.2). In combination these procedures gave 1,500-1,800 times purification of ADPase relative to plasma. The purest fraction contained ATPase, ADPase and AMPase in a 0.17:1.00:2.92 proportion, quite different from their 5.34:1.00:5.34 proportion in plasma. Adenosine deaminase and adenylate kinase were not present in the purest fraction, whereas nucleoside diphosphokinase appeared to be present.The purified ADPase was stimulated by low concentrations of Mg2+ and Mn2+, whereas high concentrations were inhibitory. This inhibition could not be explained by an increase in the ionic strength. Ca2+ and Zn2+ were inhibitory at all concentrations used (0-3 mM). Lineweaver-Burke plots were linear for both ADPase and ATPase in the 0−4 x 10-5 M substrate range, and both enzymes had Km = 1.1 x 10−5 M. Increase of the substrate concentration above 4 x 10−5M gave deviation from MichaelisMenten kinetics, and Eadie-Hofstee plots indicated the presence of “high-Km” ADPase and ATPase. The latter enzymes were not studied.Déphosphorylation of 3H-ADP by purified “low-Km” ADPase was reduced by nonradioactive diphosphates of guanosine, inosine, cytidine and uridine in the same way as when nonradioactive ADP was used. Nonradioactive AMP also reduced dephosphorylation of 3H-ADP, whereas nonradioactive ATP did not.Cyanide, cysteine and tartrate inhibited “low-Km” ADPase whereas p-chloromercuribenzoate, p-chloromercuribenzoesulphonate and N-ethylmaleimide had no effect. EDTA inhibited the enzyme activity in a way that could not be abolished by excess Mg2+. Purified plasma “low-Km” ADPase thus appears to be an unspecific enzyme, as one and the same active site does not seem to distinguish between the base moiety of nucleoside diphosphates, and catalyzes hydrolysis of phosphate esters as well as pyrophosphate bonds. The relation between plasma ADPase and ATPase remains unclear.


2021 ◽  
Vol 3 (2) ◽  
pp. 25-32
Author(s):  
M. Abd. AbdEl-Mongy ◽  
M.F. Rahman ◽  
Mohd Yunus Shukor

Physical or chemical procedures could efficiently remove contaminants including pesticides such as carbamates from high concentrations of toxicants. Bioremediation, on the other hand, is frequently a less expensive option in the long term when used at low concentrations. Isolation of multiple toxicants removing microorganisms is the goal of bioremediation. In this paper we report on the molybdenum reduction of the bacterium and its ability to grow on the carbamates carbofuran and carbaryl as carbon sources. Both the carbamates carbofuran and carbaryl cannot support molybdenum reduction when used as the sole carbon sources. Between pH 6.0 and 6.8 and between 30 and 34 oC, the bacterium is most efficient in converting molybdate to Mo-blue. For molybdate reduction, glucose was shown to be the strongest electron donor, with maltose and sucrose coming in second and third, respectively, and d-mannitol and d-adonitol coming in last. Phosphate concentrations of 2.5 to 7.5 mM and molybdate concentrations of 20 to 30 mM are also needed. Identical to that of a decreased phosphomolybdate, the Mo-blue produced by the new Mo-reducing bacteria has an absorption spectrum similar to prior Mo-reducing bacteria. Inhibition of molybdenum reduction was 73.3, 50.1, 50.1 and 20.7 percent, respectively, by mercury, copper, silver and lead at 2 ppm. The bacterium was tentatively identified as Serratia sp. strain Amr-4 after biochemical investigation. This bacterium's ability to detoxify a variety of toxicants is highly sought after, making it a significant bioremediation agent.


1974 ◽  
Vol 31 (01) ◽  
pp. 072-085 ◽  
Author(s):  
M Kopitar ◽  
M Stegnar ◽  
B Accetto ◽  
D Lebez

SummaryPlasminogen activator was isolated from disrupted pig leucocytes by the aid of DEAE chromatography, gel filtration on Sephadex G-100 and final purification on CM cellulose, or by preparative gel electrophoresis.Isolated plasminogen activator corresponds No. 3 band of the starting sample of leucocyte cells (that is composed from 10 gel electrophoretic bands).pH optimum was found to be in pH range 8.0–8.5 and the highest pH stability is between pH range 5.0–8.0.Inhibition studies of isolated plasminogen activator were performed with EACA, AMCHA, PAMBA and Trasylol, using Anson and Astrup method. By Astrup method 100% inhibition was found with EACA and Trasylol and 30% with AMCHA. PAMBA gave 60% inhibition already at concentration 10–3 M/ml. Molecular weight of plasminogen activator was determined by gel filtration on Sephadex G-100. The value obtained from 4 different samples was found to be 28000–30500.


1981 ◽  
Vol 38 (10) ◽  
pp. 1283-1285 ◽  
Author(s):  
J. G. Eales

Chronic exposure of fed immature rainbow trout (Salmo gairdneri) to a low ambient thiourea (TU) concentration did not depress circulating levels of T4 (thyroxine) or triiodothyronine, T4 degradation rate, or T4 deiodination rate indicating no significant T4 influence on thyroidal hormone output. However, TU increased the hematocrit and decreased distribution spaces for iodide and T4, indicating direct sensitivity of extrathyroidal processes to TU.Key words: thiourea, thyroxine, hematocrit, iodide metabolism, rainbow trout


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