scholarly journals Purification and partial characterization of superoxide dismutase from the thermophilic bacteria Thermothrix sp

2004 ◽  
Vol 69 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Svetlana Seatovic ◽  
Ljubinka Gligic ◽  
Zeljka Radulovic ◽  
Ratko Jankov

Superoxide dismutase (SOD; EC 1.15.1.1), a high molecular weight component of the antioxidant defense system, provided promising results in the treatment of oxidative damage. Thermothrix sp., isolated from thermal spa water in Serbia, showed high superoxide dismutase activity. The SOD, from cell free extract, was purified to homogenity by ammonium sulfate precipitation, Sephadex G 75 gel filtration chromatography and QAE Sephadex ion exchange chromatography. The specific activity of the purified enzyme was 9191 U/mg. The purified enzyme was analyzed and partially characterized. SOD was localized in polyacrylamide gel by activity staining, based on the reduction of nitroblue tetrazolium (NBT) by superoxide. The enzyme molecular weight determined by gel chromatography is 37 kD. According to SDS PAGE it is composed of two subunits of equal size, joined by noncovalent interactions. The isoelectric point, assessed by isoelectric focusing is 5.3. The optimum pH for enzyme activity was in the range of 8 to 10. The optimum temperature for SOD activity was 60 ?C. After one hour of incubation at 40, 50 and 60 ?C the SOD activity increases, but at 80 ?C, the SOD is denaturated. After 24 hours of incubation at 25 ?C SO Dactivity only slightly decreases.

Parasitology ◽  
1998 ◽  
Vol 117 (6) ◽  
pp. 555-562 ◽  
Author(s):  
L. PIACENZA ◽  
R. RADI ◽  
F. GOÑI ◽  
C. CARMONA

The levels of superoxide dismutase (SOD) were determined in detergent-soluble, somatic and excretion–secretion (E–S) preparations from adult Fasciola hepatica using the xanthine oxidase system and visualized in substrate gels. Compared to detergent-soluble and somatic extracts, E–S products showed the highest SOD activity (88 ·5 U/mg), indicating active release to the medium in which parasites were maintained. SOD specific activity was also detected at high levels in E–S products from 3-week-old and 5-week-old immature migrating flukes (25 and 143 U/mg, respectively). In all preparations except for the somatic extract, the activity was characterized as cyanide-sensitive CuZn SOD. Differences in SOD isoenzyme profiles between the extracts were observed in native polyacrylamide gel electrophoresis: the somatic and detergent-soluble extracts exhibited 1 band of activity while the E–S products from immature and adults flukes contained 2 and 3 migrating bands, respectively. SOD was purified from the detergent-soluble extract and E–S products of adult worms by a combination of ultrafiltration, gel filtration on Sephacryl S-200 HR and ion-exchange chromatography on QAE Sephadex A-50. The SOD from detergent-soluble extract showed, by SDS–PAGE analysis, 1 band of 16 kDa apparent molecular weight. The SOD from E–S products showed 2 bands of 16 and 60 kDa apparent molecular weight. N-terminal sequence analysis of the 16 kDa band from the detergent-soluble preparation showed some similarity with Schistosoma mansoni cytoplasmic SOD. These enzymes may have a potential role in the evasion of the oxidative burst killing mechanism by immune cells.


2021 ◽  
Vol 58 (04) ◽  
pp. 1191-1196
Author(s):  
Huma Naz

In this experiment, effect of lead (Pb) + chromium (Cr) mixture on superoxide dismutase (SOD) in the liver of Labeo rohita at a concentration of 11.1 mgL-1 was observed. The ammonium sulphate precipitation and ion exchange chromatography techniques were successfully used to purify SOD. After purification, SOD activity of control and Pb+Cr treated fish was noted as 581.00 and 645.45 UmL-1, respectively while the specific activity was 1383.33 and 1613.62 Umg-1, respectively. The fold purification value of SOD was 2.75 and 2.45 for control and stressed fish, respectively. The recovery was calculated as 77.06 and 57.43% for control and stressed fish, respectively. The results of kinetic characterization showed that SOD form control and exposed fish had maximum activity at pH 6.5 and 7.0. Temperature also had a significant effect on activity of SOD. The SOD activity was measured maximum at 30°C for both control and Pb+Cr exposed fish. The Km value of liver SOD for control and Pb+Cr treated L. rohita was calculated as 1.48 and 0.62 mM, respectively. The value of Vmax for SOD from liver of control and Pb+Cr exposed fish was 1000 and 570 U mL-1, respectively. The enthalpy of denaturation (∆H*) for liver SOD from control and Pb+Cr exposed L. rohita was computed as 3.492 and 2.802 KJ mol-1 at 40°C, respectively and these values were dropped off with increasing the temperature until it remains 3.251 and 2.561 KJ mol-1 at 70°C, respectively. The free energy of thermal denaturation (ΔGº) of liver SOD was slightly increased with increasing temperature until 75°C which shows its resistance against heat. The values of ΔGº was observed as 58.03 and 57.95 KJ mol-1 for control and exposed fish at 40°C, respectively while the same was increased upto 62.37 and 62.00 KJ mol-1 at 70°C, respectively. It was concluded from negative value of ΔS* (entropy of inactivation) that the SOD is stable thermodynamically.


1978 ◽  
Vol 175 (1) ◽  
pp. 35-46 ◽  
Author(s):  
A J MacGillivray ◽  
C Johnston ◽  
R MacFarlane ◽  
D Rickwood

After labelling of mouse liver nuclei with [gamma-32P]ATP in vitro, 10-20% of the radioactivity incorporated into the saline-soluble nuclear and HAP2 chromatin fractions was located in a low-molecular-weight component (component 10) with pI near 4.5 in urea. By using combinations of ion-exchange chromatography, preparative thin-layer isoelectric focusing and gel filtration, this component was isolated from both nuclear fractions. Recovery from the saline-soluble fraction was poor under conditions that allow endogenous phosphatases to be active. Component 10 was shown to be a phosphoprotein on the basis of enzyme-digestion experiments and the detection of phosphoserine and phosphothreonine. The 32P radioactivity did not appear to be associated with phosphorylated basic amino acids. Its molecular weight was determined by gel chromatography and electrophoresis in sodium dodecyl sulphate/polyacrylamide gels as approx. 10000, and tryptic digestion of the reduced carboxymethylated protein in urea yielded two 32P-labelled peptides. It has not been possible as yet to assign a function to component 10, though its similarity to other low-molecular-weight acidic proteins is discussed.


Biologia ◽  
2014 ◽  
Vol 69 (12) ◽  
Author(s):  
Hayet Ben Khaled ◽  
Naourez Ktari ◽  
Rayda Siala ◽  
Noomen Hmidet ◽  
Ahmed Bayoudh ◽  
...  

AbstractSuperoxide dismutase (SOD) is an enzyme that protects against oxidative stress from superoxide radicals in living cells. This enzyme was extracted from sardinelle (Sardinella aurita) viscera, purified and characterized. The Cu/Zn-SOD was purified to homogeneity by the three-step procedure consisting of the heating at 65°C for 15 min, precipitation with ammonium sulphate (30–60%, w/v) and Sephadex G-100 gel filtration with a 7.17-fold increase in specific activity. The molecular weight of the native enzyme was estimated to be 40 kDa by G-125 gel filtration on HPLC column and that of the subunit mass, deduced by sodium dodecyl sulphate-polyacrylamide gel electrophoresis, was 20 kDa. Thus the native enzyme appeared to be a homodimer. The optimum pH and temperature for the purified SOD activity were determined to be pH 7.0 and 40°C, respectively. It retained more than 85% of its initial activity after 1 h of incubation at 50°C. The enzyme had a broad stability pH range of 6.0–9.0. The N-terminal sequence of the purified enzyme was VLKAVCVLKGTGEVT. This sequence exhibited a high degree of sequence similarity with other fish Cu/Zn SODs.


1976 ◽  
Vol 83 (3) ◽  
pp. 466-482 ◽  
Author(s):  
D. Graesslin ◽  
F. A. Leidenberger ◽  
V. Lichtenberg ◽  
D. Glismann ◽  
N. Hess ◽  
...  

ABSTRACT Serum fractions from normal subjects obtained by gel chromatography have been investigated using three different assay systems: radioimmunoassay (RIA), radioligand receptor assay (RRA), and testosterone production assay (TPA). The bulk of immunoassayable and "bioassayable" LH-activity was found in two fractions differing widely in their molecular size. The slower moving component, designated as "little" LH, migrated identical to the radioiodinated pituitary hormone (LER 960) with a molecular weight of about 30 000, while "big" LH appeared in an elution volume consistent with a molecular weight range between 140 000 and 180 000. Concordance was seen between the LH-activities measured in all three assay systems. The RRA/RIA ratio varied between 1.6 and 8.9, the RRA/TPA ratio was close to unity. Treatment with 6 m urea and 0.1 % mercaptoethanol and also, exposure to different pH values and salt concentrations did not change the elution position of the two LH components. Also, "big" and "little" LH appeared unaltered after re-filtration and no conversion each other could be found. In another experiment injection of gonadotrophin releasing hormone (Gn-RH) into a male induced a profound shift of LH towards the low molecular weight species. Kinetic uptake studies with "big" and "little" LH using RRA showed identical affinities to the receptor preparation. Ion exchange chromatography of serum, however, did not give two LH components, indicating no major differences in charge properties. This finding could be confirmed by preparative gel isoelectric focusing. The RRA potencies following gel filtration were in good agreement with that applied to the column, however, the immunological activities exceeded that of loaded by a factor 3–4. A new aspect of serum LH heterogeneity is the finding of a low molecular substance (mol. weight approximately 1000) in the outer dialysate of serum, which has LH like activity in all three assay systems.


1992 ◽  
Vol 12 (1) ◽  
pp. 15-21
Author(s):  
S. Kojima ◽  
K. Nara ◽  
Y. Inada ◽  
S. Hirose ◽  
Y. Saito

Platelet aggregation activity due to platelet-activating factor (PAF) was detected at high molecular weight (HMW) and low molecular weight fractions after gel-filtration chromatography of cell lysate of endothelial cells. [3H]PAF added to the cell lysate was similarly distributed after chromatography. The radioactivity associated with HMW fraction was not reduced by digesting the lysate with trypsin, suggesting that PAF was not making complexes with proteins but was included in lipid vesicles in cell lysate. Further evidence showed that an unknown specific factor(s) was needed to form these PAF-containing lipid vesicles. Radioactivity was not found in HMW fraction when [3H]PAF was mixed with cell lysate of vascular smooth muscle cells. When monomeric PAF was added to endothelial cell lysate, the specific activity of aggregation decreased to the level exerted by endogenous PAF-containing lipid vesicles due to incorporation into lipid vesicles. PAF in the form of lipid vesicles was more stable in plasma than monomeric form.


Author(s):  
Ismat Bibi ◽  
Haq Nawaz Bhatti

This study deals with purification and characterization of lignin peroxidase (LiP) isolated from Agaricus bitorqus A66 during decolorization of NOVASOL Direct Black dye. A laboratory scale experiment was conducted for maximum LiP production under optimal conditions. Purification & fractionation of LiP was performed on DEAE-Sepharose ion exchange chromatography followed by Sephadex G-50 gel filtration. The purified LiP has a specific activity of 519 U/mg with 6.73% activity recover. The optimum pH and temperature of purified LiP for the oxidation of veratryl alcohol were 6.8 and 45 °C, respectively. Michaelis-Menten kinetic constants (Vmax and Km) were determined using different concentrations of veratryl alcohol (1-35 mM). The Km and Vmax were 16.67 mM and 179.2 U/mL respectively, for veratryl alcohol oxidation as determined from the Lineweaver-Burk plot. Thermal inactivation studies were carried out at different temperatures to check the thermal stability of the enzyme. Enthalpy of activation decreased where Free energy of activation for thermal denaturation increased at higher temperatures. A possible explanation for the thermal inactivation of LiP at higher temperatures is also discussed.


1972 ◽  
Vol 130 (1) ◽  
pp. 211-219 ◽  
Author(s):  
Colin H. Self ◽  
P. David J. Weitzman

Two isoenzymes of NADP-linked isocitrate dehydrogenase have been identified in Acinetobacter lwoffi and have been termed isoenzyme-I and isoenzyme-II. The isoenzymes may be separated by ion-exchange chromatography on DEAE-cellulose, by gel filtration on Sephadex G-200, or by zonal ultracentrifugation in a sucrose gradient. Low concentrations of glyoxylate or pyruvate effect considerable stimulation of the activity of isoenzyme-II. The isoenzymes also differ in pH-dependence of activity, kinetic parameters, stability to heat or urea and molecular size. Whereas isoenzyme-I resembles the NADP-linked isocitrate dehydrogenases from other organisms in having a molecular weight under 100000, isoenzyme-II is a much larger enzyme (molecular weight around 300000) resembling the NAD-linked isocitrate dehydrogenases of higher organisms.


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.


2021 ◽  
Vol 9 (2) ◽  
pp. 24-30

Streptokinase is a fibrinolytic enzyme and a product of β-hemolytic Streptococci strains. This enzyme is used as a medication to break down clots in some cases of heart disease. Streptococcus equisimilis, a species of group C Streptococci, is widely used for the production of streptokinase by fermentation technology. In this study, the sugarcane bagasse fermentation medium was optimized for metal ions (KH2PO4, MgSO4.7H2O, CaCO3 and NaHCO3) at various levels to attain the maximal production of streptokinase. Sugarcane bagasse was used due to its profuse availability and as an ideal substrate for microbial processes for the manufacturing of value-added products. The results showed that maximal streptokinase production was found at 0.04% KH2PO4, 0.04% MgSO4.7H2O, 0.15% NaHCO3 and 0.04% CaCO3. Finally, the optimized medium resulted in 84.75 U/mg specific activity and 74.5% recovery. The purification process was carried out simultaneously using ammonium sulfate precipitation, ion-exchange chromatography, and gel filtration. Finally, a purified sample of streptokinase was run on SDS-PAGE and resolute 47 kDa molecular weight. The use of β-hemolytic Streptococci to obtain streptokinase is not free from health risks and is related to anaphylaxis. This study provides a way forward for the cost-effective ways to obtain streptokinase for the treatment of thrombosis.


Sign in / Sign up

Export Citation Format

Share Document