scholarly journals Isolation and partial characterization of an acid phosphatase from Artemisia vulgaris pollen extract

2002 ◽  
Vol 67 (8-9) ◽  
pp. 567-572 ◽  
Author(s):  
Tanja Cirkovic-Velickovic ◽  
Marija Gavrovic-Jankulovic ◽  
Mirjana Bukilica ◽  
Ljuba Mandic ◽  
Spomenka Petrovic ◽  
...  

An acid phosphatase from an extract of mugwort (Artemisia vulgaris) pollen was purified by a factor of 48 by a combination of ion exchange and gel-chromatography. The molecular weights of the enzyme were 76 kDa and 73 kDa, determined by gel filtration on a Sephadex G-100 sf column and by SDS PAGE(under reducing and non-reducing conditions), respectively. In analytical isoelectrofocusing, the enzyme appears as two very close bands pI at about 4.2. The optimum pH for the enzyme is 5.4. The apparent Km for p-nitrophenyl phosphate was estimated to be 0.16mM. The purified enzyme has broad specificity, and hydrolyses p-nitrophenyl phosphate and ?-naphthyl phosphate. Pyrophosphate and O-phospho-L-tyrosine were estimated to be the best substrates for this enzyme as potential in vivo substrates. The enzyme is inhibited competitively by phosphate (Ki = 1.25 mM), molybdate (Ki = 0.055 mM) and pyrophosphate (Ki = 6.7 mM) and non-competitively by fluoride (Ki = 9.8 mM). Metal ions such as Hg2+, Cu2+ and Zn2+ express an inhibitory effect on the enzyme, while the enzyme is slightly activated by non-ionic detergents, Tween 20 and Triton X-100. There is no change in the enzyme activity in the presence of tartrate, citrate, EDTA, 1,10-phenanthroline and sulfhydryl-group modifiers such as p-chloromercuribenzoate and N-ethylmaleimide.

2011 ◽  
Vol 63 (3) ◽  
pp. 747-756 ◽  
Author(s):  
A.K.M. Asaduzzaman ◽  
Habibur Rahman ◽  
Tanzima Yeasmin

An acid phosphatase has been isolated and purified from an extract of a germinating black gram seedling. The method was accomplished by gel filtration of a germinating black gram seedling crude extract on sephadex G-75 followed by ion exchange chromatography on DEAE cellulose. The acid phosphatase gave a single band on SDS-polyacrylamide slab gel electrophoresis. The molecular weight of the acid phosphatase determined by SDS-polyacrylamide slab gel electrophoresis was estimated to be 25 kDa. The purified enzyme showed maximum activity at pH 5 and at temperature of 55?C. Mg2+, Zn2+ and EDTA had an inhibitory effect on the activity of the acid phosphatase. Black gram seedling acid phosphatase was activated by K+, Cu2+ and Ba2+. The Km value of the enzyme was found to be 0.49 mM for pNPP as substrate.


1987 ◽  
Vol 57 (1) ◽  
pp. 35-44 ◽  
Author(s):  
D. E. Coppen ◽  
N. T. Davies

1. Weanling male rats were maintained on diets containing 5, 10, 20, 40, 80 or 160 mg zinc/kg for 14 d. On day 15 they received 65Zn either by intraperitoneal injection or in a test meal containing 20 mg Zn/kg. After dosing, the rats were again maintained on the diets they had received previously.2. Whole-body 65Zn retention was measured immediately after dosing and daily for a further 9 d. From regression analysis of the semi-logarithmic plots of 65Zn retention from 0 to 192 h after 65Zn administration, the true extent of 65Zn absorption and the biological half-life (t1/2) of body 65Zn stores were calculated.3. At the end of the experiment, the rats were killed and the entire small intestines of some rats from each group were rapidly flushed out to remove food and faecal residues, frozen in liquid nitrogen and stored under an atmosphere of N2 at –20° before separation of cytosolic Zn-binding fractions by gel filtration on Sephadex G–75.4. The results suggest that rats which received diets that were either deficient(5 mg Zn/kg), marginal (10 mg Zn/kg) or adequate (20–80 mg Zn/kg) in Zn achieved homeostatic regulation of body Zn by changes in both the extent of Zn absorption and excretion. However, when Zn supply was excessive, increasing from 80 to 160 mg Zn/kg, no further changes were seen in Zn absorption, and homeostatic control appeared to be effected entirely by changes in rates of body Zn loss.5. Gel chromatography of intestinal cytosol on Sephadex G-75 revealed that Zn was associated with two major fractions. The first (peak 1) had a molecular weight (MW) > 75 kdaltons and the second (peak 2), a MW of approximately 10 kdaltons and was assumed to be metallothionein.6. There was no obvious relation between the amount of Zn bound to peak 1 and dietary Zn content. In contrast, the amount of Zn recovered in peak 2 increased linearly with increasing dietary Zn content.7. Comparisons between the effect of dietary Zn content on Zn bound to peak 2 and 65Zn retention may, depending on the range of Zn intakes, indicate possible roles for intestinal metallothionein in the control of Zn absorption or excretion.8. A study of the effects of dietary dose of 65Zn on the extent of 65Zn absorption in rats of normal Zn status indicated a possible biphasic relation. At low doses (5–40 mg Zn/kg) 65Zn absorption appeared to exhibit a curvilinear response to increasing 65Zn dose, indicating possibly a saturable process. At higher doses (40–160 mg Zn/kg) the capacity of this process appeared to be exceeded and 65Zn absorption increased in a linear fashion.


Author(s):  
R. Castillo ◽  
S. Maragall ◽  
J. A. Guisasola ◽  
F. Casals ◽  
C. Ruiz ◽  
...  

Defective ADP-induced platelet aggregation has been observed in patients treated with streptokinase. This same effect appears “in vitro” when adding SK to platelet rich plasma (PRP). Classic hemophilia and normal platelet poor plasmas (PPP) treated with SK inhibit the aggregation of washed platelets; plasmin-treated normal human serum also shows an inhibitory effect on platelet aggregation. However, von Willebrand SK-treated plasmas do not inhibit the aggregation of washed platelets. The same results appear when plasmas are previously treated with a rabbit antibody to human factor VIII.This confirms that the antiaggregating effect is mainly linked to the digested factor VIII related antigen.The inhibition of ADP-induced platelet aggregation has been proved in gel filtration-isolated and washed platelets from SK-treated PRP.Defective ristocetin-induced platelet aggregation has also been observed- This action does not appear in washed platelets from SK-treated PRP in presence of normal PPP, but it does in presence of SK-treated PPP, which suggests that the inhibition of the ristocetin-induced aggregation is due to the lack of factor VIII and not to the factor VIII-related products.Heparin, either “in vivo” or “in vitro”, has corrected the antiaggregating effect of SK.


1993 ◽  
Vol 75 (1) ◽  
pp. 167-172 ◽  
Author(s):  
D. C. Crossman ◽  
M. R. Dashwood ◽  
G. W. Taylor ◽  
R. Wellings ◽  
R. W. Fuller

The mechanism of action of the antiasthmatic drug sodium cromoglycate (SCG) is unclear. One possibility is that SCG antagonizes the effects of the tachykinin substance P (SP), an agent known to cause airway edema. However, when SP is inhaled by humans, it has no demonstrable effect on airway function; therefore, the possibility that SCG prevents SP-induced changes in microvascular permeability was examined in human skin in vivo where potent edema-producing effects are seen. SCG (5–500 nmol) caused significant (P < 0.05) dose-dependent inhibition of SP-induced edema (wheal) formation when coadministered by intradermal injection. There was no effect on the nonreceptor-mediated flare response. SCG also significantly (P < 0.05) inhibited the wheal response to the related tachykinin neurokinin B but had no inhibitory effect on the cutaneous responses to histamine and prostaglandin E2. In addition, SCG (0.1–10 mM) caused dose-dependent inhibition of binding of SP labeled with 125I-labeled Bolton-Hunter to a number of tissues known to contain SP binding sites, as assessed by autoradiography. These concentrations were equivalent to the final concentrations of SCG found to inhibit the wheal response in the skin. The possibility that SCG interacted with SP was investigated both by gel filtration and high-performance liquid chromatography. No strong interaction was demonstrated with an 8,000 M excess of SCG under both hydrophobic and hydrophilic conditions. These results raise the possibility that SCG may have tachykinin antagonist properties.


2020 ◽  
pp. 18-26
Author(s):  
I. Sani ◽  
A.A. Umar ◽  
S.A. Jiga ◽  
F. Bello ◽  
A. Abdulhamid ◽  
...  

Several studies have been reported on active peptides isolated from some medicinal plants, which were effective inhibitors against snake venom induced toxicities. Hence, the aim of this research work was to isolate, purify and characterize an antisnake venom plant peptide from Bauhinia rufescens seed that can serve as potential alternative to serum-based antivenins. B. rufescens seed was collected, duly identified, authenticated and processed. The peptide was isolated from the seed and purified using gel filtration chromatography and SDS-PAGE and then named as BRS-P19. Venom Phospholipase A2 (VPLA2) was used for the study and was isolated from Naja nigricollis venom. Albino mice of both sexes were used for in vivo experiments. They were divided into seven (7) groups of three (3) mice each. Group 1 served as normal control, group 2 were injected with VPLA2 only, group 3 and 4 were injected with VPLA2 then treated with BRS-P19 at doses of 0.2 and 0.4 mg/kg b.w. respectively, while mice in group 5 were injected with VPLA2 then treated with standard antivenin, group 6 and 7 were injected with VPLA2 followed by administration of ascorbic acid and α-tocopherol respectively. In all the groups, hepatic and renal levels of reactive oxygen species (ROS), lipid peroxidation (MDA) and activities of antioxidant enzymes were determined. The results showed that, the BRS-P19 has molecular weight of ~19kD. Its percentage in vitro inhibitory effect against VPLA2 was 91.85 ± 0.32%. For the in vivo study, the animals treated with 0.4 mg/kg b.w. of the BRS-P19 showed a significant (P<0.05) decrease in the hepatic and renal ROS and MDA levels when compared with the VPLA2 untreated group. But, the activities of the antioxidant enzymes in all the treated groups were significantly (P<0.05) increased by the BRS-P19 at 0.4 mg/kg b.w. when compared to the VPLA2 untreated group. Based on these findings, it has been established that, BRS-P19 has antisnake venom effect through inhibition of VPLA2 and antioxidant activity as the possible mechanisms of action.


1976 ◽  
Vol 36 (01) ◽  
pp. 014-026 ◽  
Author(s):  
M. B Donati ◽  
R Verhaeghe ◽  
D. E Culasso ◽  
J Vermylen

SummaryUsing gel chromatography, fibrinogen derivatives present in purified systems or in biological fluids were separated and partially characterized. Eight groups of fibrinogen derivatives could be separated by gel filtration through 6% agarose in large columns, four with an elution volume smaller and four groups with an elution volume larger than that of fibrinogen. Careful calibration of the column allowed estimation of the diffusion coefficients of some of the derivatives and, thus, comparison with derivatives previously identified. Three, rather than two, groups of intermediate derivatives were observed during the degradation of human fibrinogen by plasmin in vitro or in vivo. One of these had a marked tendency to polymerize.A rather distinct difference in elution pattern was found between plasma obtained during streptokinase administration and from patients with intravascular coagulation.


1992 ◽  
Vol 1 (1) ◽  
pp. 49-54 ◽  
Author(s):  
W. M. S. C. Tamashiro ◽  
B. M. Tavares-Murta ◽  
F. Q. Cunha ◽  
M. C. Roque-Barreira ◽  
R. M. D. Nogueira ◽  
...  

Inhibitory effect upon neutrophil migration to the inflammatory focus was previously detected in the cell-free incubation fluid of lipopolysaccharide (LPS)-stimulated macrophage monolayers. In the present study we showed that the neutrophil recruitment inhibitory activity from this supernatant was mainly detected in a fraction (P2) obtained by gel filtration chromatography on Sephacryl S-300. P2 fraction was able to inhibit ‘in vivo’ neutrophil emigration induced by different inflammatory stimuli, but it did not affect ‘in vitro’ neutrophil chemotaxis induced by FMLP. When injected intravenously, P2 inhibited oedema induced by carrageenin or immunological stimulus but not the oedema induced by dextran, thus affecting cell-dependent inflammatory responses. It was observed that P2 also induced neutrophil migration when injected locally in peritoneal cavities. This activity was significantly reduced by pretreatment of the animals with dexamethasone. Cytokines, such as IL-8 and TNF-α that are known to exhibit inhibitory effect upon neutrophil migration, were not detected in P2 fraction by highly sensitive assays. Overall the results suggest the existence of a novel cytokine exhibiting ‘in vivo’ neutrophil inhibitory activity, referred as NRIF.


1975 ◽  
Author(s):  
J. P. Attain ◽  
H. A. Cooper ◽  
R. H. Wagner

Small active factor VIII fragment was prepared for infusion studies by agarose gel chromatography of a canine factor VIII preparation in 0.25 M CaCl2. The material was concentrated, and the Ca2+ was removed. Three hemophilic dogs received four infusions of 13 to 30 u of factor VIII activity per kg of body weight. Immediate recovery of factor VIII activity varied from 0 to 25% of the calculated values. Most of the activity disappeared within two hours after infusion, but whole blood clotting times were still shortened after 12 hours in two experiments. Control studies using cryoprecipitate were satisfactory. Plasmas of three of six hemophilic dogs showed weak inhibition of the small active factor VIII fraction in vitro. The inhibitory effect was present in these hemophilic plasmas after heating to 56° C for 1 hour. The rapid disappearance of activity after transfusion is not completely explained by this inhibitory effect, as rapid in vivo disappearance was also observed where no inhibition was detectable. It appears that use of small active factor VIII does not offer a practical means for intravenous, subcutaneous, or intramuscular administration.(Supported by NIH Grants HL-6350, HL-1648).


1984 ◽  
Vol 62 (2) ◽  
pp. 385-391 ◽  
Author(s):  
Sheikh Mehboob Basha

An acid phosphatase (EC 3.1.3.2) from peanut (Arachis hypogaea L.) seed has been purified 433-fold by ammonium sulfate fractionation, gel filtration, and ion-exchange chromatography. The purified preparation was found to be homogeneous by electrophoresis and gel filtration. The molecular weight of the enzyme was estimated to be approximately 240 000 and it was found to be composed of six identical subunits, each with an apparent molecular weight of 42 500. Following isoelectric focusing, the isolectric point (pI) of the enzyme was found to be around pH 5.6. The apparent Km value with p-nitrophenyl phosphate as substrate was 2 ? 10−1 μM. The enzyme was inhibited by Hg2+, Fe2+, Cu2+, Zn2+, Pb2+, and F−. Higher concentrations (2–50 μM) and long incubation periods (60–90 min) with Ca2+ and Mg2+ ions were shown to activate the enzyme. This enzyme showed no effect toward phosphorylated sugars but appear to hydrolyze ATP, ADP, AMP, and β-glycerophosphate.


1963 ◽  
Vol 41 (1) ◽  
pp. 1727-1731 ◽  
Author(s):  
D. W. A. Roberts

A survey of the inhibitory effect of various ribonucleosides, deoxyribonucleosides, sugars, phenols, and vitamins on the hydrolysis of 17 phosphatase substrates has been made. The more soluble ribonucleosides and deoxyribonucleosides inhibited the enzymatic hydrolysis of adenosine 5′-phosphate, phenolphthalein diphosphate, phenylphosphate, p-nitrophenyl phosphate, and in some cases the hydrolysis of adenosine 3′-phosphate, adenosine 2′-phosphate, and riboflavin 5′-phosphate. A 0.02 M concentration of orthophosphate inhibited the hydrolysis of all the compounds tested except adenosine 5′-phosphate and phenolphthalein diphosphate.These results, together with earlier findings, are discussed in terms of the concept that wheat leaf press juice contains two types of acid phosphatase, namely, β-glycerophosphatase and adenosine 5′-phosphatase. These two types of enzyme appear to have partially overlapping substrate specificities.


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