scholarly journals Peroxidase from infected fruit of Solanum sp. grown in Nsukka

2019 ◽  
Vol 54 (2) ◽  
pp. 131-138
Author(s):  
Omeje KO ◽  
Eze SOO ◽  
FC Chilaka

In this study, we characterized the activity of peroxidase a quality control enzyme from the infected fruit of Solanum sp. Peroxidase was purified to homogeneity by ammonium sulfate precipitation, dialysis, ion exchange chromatography and size exclusion chromatography. The molecular weight of the native enzyme was 63000 da. The enzyme was shown to have two iso-enzymes with distinct optimum pH of 4.5 and 7.0 and optimum temperature of 40 and 70⁰C. The purified enzyme had broad substrate specificity with o-dianisidine being the ideal substrate. Na+, Ca2+, Mg2+, Mn2+, Cu2+, Al3+ were shown to be activators of the enzyme, while the peroxidase activity was severely inhibited by Co2+. Bangladesh J. Sci. Ind. Res.54(2), 131-138, 2019

2016 ◽  
Vol 63 (3) ◽  
Author(s):  
Marcin Grąz ◽  
Kamila Rachwał ◽  
Radosław Zan ◽  
Anna Jarosz-Wilkołazka

Oxalate oxidase was identified in mycelial extracts of a basidiomycete Abortiporus biennis strain. Intracellular enzyme activity was detected only after prior lowering of the pH value of the fungal cultures by using oxalic or hydrochloric acids. This enzyme was purified using size exclusion chromatography (Sephadex G-25) and ion-exchange chromatography (DEAE-Sepharose). This enzyme exhibited optimum activity at pH 2 when incubated at 40°C, and the optimum temperature was established at 60°C. Among the tested organic acids, this enzyme exhibited specificity only towards oxalic acid. Molecular mass was calculated as 58 kDa. The values of Km for oxalate and Vmax for the enzyme reaction were 0.015 M and 30 mmol min-1, respectively.


1996 ◽  
Vol 51 (5-6) ◽  
pp. 429-431 ◽  
Author(s):  
M.O. Ilori ◽  
O.O. Amund ◽  
O. Omidiji

Abstract A proteolytic enzyme produced by a cassava-ferment­ing strain of Micrococcus luteus was extracted and puri­fied 50-fold by gel filtration and ion exchange chromatography. The optimum pH for the enzyme was 7.0, the optimum temperature 25 °C, the apparent molecular weight 42 kDa and the Km value, 0.45 mg ml-1 with casein as substrate. The enzyme was stimulated by Ca2+ and Mg2+ but inhibited by Zn2+ and Co2+ ions. Other inhibitors were EDTA, KCN, citric acid and L-cysteine indicating the enzyme to be a metalloprotease.


1985 ◽  
Vol 63 (11) ◽  
pp. 1160-1166 ◽  
Author(s):  
Pierre Gondé ◽  
Robert Ratomahenina ◽  
Alain Arnaud ◽  
Pierre Galzy

The exocellular enzyme β-glucosidase of Candida molischiana was studied. This strain is able to ferment soluble cellodextrins. The enzyme was partially purified by ion-exchange chromatography and gel filtration. The molecular weight of this enzyme was 120 000; its optimum pH was between 4 and 4.5 and its optimum temperature was 60 °C. This enzyme was active against different soluble glucosides and was inhibited by p-chloromercuribenzoate, gluconolactone, and glucose. A "glucosyltransferase" activity appeared in the presence of ethanol. The biosynthesis of the enzyme was constitutive but repressed by glucose.


Author(s):  
Lia Siti Nur'amaliyah ◽  
Dewi Seswita Zilda ◽  
Nisa Rachmania Mubarik

Streptomyces sp. TTA 02 SDS 14 is a transglutaminase producing bacteria which previously had been  screened along with more than one hundred isolates. This research aimed to purify and characterize transglutaminase from this strain. Transglutaminase was purified from crude enzyme by ultrafiltration, Q-Sepharose ion exchange chromatography and Sepacryl S200 size exclusion chromatography sequentially, obtaining yield and purification fold of  1.36%  and 27 folds, respectively. The molecular weight of the purified transglutaminase was 72 kDa detected by zymogram gel electrophoresis. The optimum temperature and pH were 50°C and 6. The transglutaminase was stable at 45°C and could be activated in the presence of 5 mM and 10 mM of Na+, K+, Li+,Ca2+, Mg2+, BPB (4-bromo-phenacyl bromide), and IAA (iodo acetamide acid), but the activity was inhibited by  the presence of Cu+, Zn2+, and PMSF (phenyl methyl sulfonyl fluoride).


1995 ◽  
Vol 41 (12) ◽  
pp. 1057-1062 ◽  
Author(s):  
Fernando Costa Amaral ◽  
Rogelio Lopes Brandäo ◽  
Jacques Robert Nicoli ◽  
Claudio Henrique Dias Ortiz

Acid and neutral trehalase activities (optimum pH of 4.6 and 6.8, respectively) from Fusarium oxysporum var. lini were studied separately through partial isolation by ammonium sulfate precipitation followed by ion-exchange chromatography on DEAE-Sephacel for neutral enzyme, or using some of their differential properties. Acid activity was unaffected by 1 mM of Ca2+, Mg2+, Mn2+, Ba2+, or EDTA. Contrarily, the neutral enzyme was activated by Ca2+with an apparent Kaof 0.15 mM; was inhibited by EDTA, Zn2+, Hg2+, or Mg2+-ATP; and showed an increase in activity by the raise of buffer ionic strength or by the addition of 100 mM KCl. Acid and neutral enzymes have, respectively, an apparent optimum temperature of 45 and 30 °C, an apparent Kmfor trehalose of 0.43 and 8.45 mM, and an apparent Mrof 160 000 and 100 000 (by glycerol gradient ultracentrifugation). Acid trehalase was specifically inhibited by acetate buffer and more stable at 50 °C than the neutral enzyme. Neutral enzyme exhibited a pi of 6.2 by isoelectric focusing. Contrary to neutral trehalases from other fungi, the enzyme from Fusarium oxysporum var. lini was not activated in crude extract by treatment with Mg2+-ATP in the presence of cAMP and not inactivated by alkaline phosphatase from Escherichia coli.Key words: acid trehalase, neutral trehalase, Fusarium oxysporum.


Author(s):  
Rasmus K. Jensen ◽  
Melanie Plum ◽  
Luna Tjerrild ◽  
Thilo Jakob ◽  
Edzard Spillner ◽  
...  

Omalizumab is a humanized anti-IgE antibody that inhibits the binding of IgE to its receptors on mast cells and basophils, thus blocking the IgE-mediated release of inflammatory mediators from these cells. Omalizumab binds to the Fc domains of IgE in proximity to the binding site of the high-affinity IgE receptor Fc∊RI, but the epitope and the mechanisms and conformations governing the recognition remain unknown. In order to elucidate the molecular mechanism of its anti-IgE activity, the aim was to analyse the interaction of omalizumab with human IgE. Therefore, IgE Fc C∊2–4 was recombinantly produced in mammalian HEK-293 cells. Functionality of the IgE Fc was proven by ELISA and mediator-release assays. Omalizumab IgG was cleaved with papain and the resulting Fab was purified by ion-exchange chromatography. The complex of IgE Fc with omalizumab was prepared by size-exclusion chromatography. However, crystals containing the complex were not obtained, suggesting that the process of crystallization favoured the dissociation of the two proteins. Instead, two structures of the omalizumab Fab with maximum resolutions of 1.9 and 3.0 Å were obtained. The structures reveal the arrangement of the CDRs and the position of omalizumab residues known from prior functional studies to be involved in IgE binding. Thus, the structure of omalizumab provides the structural basis for understanding the function of omalizumab, allows optimization of the procedure for complex crystallization and poses questions about the conformational requirements for anti-IgE activity.


1991 ◽  
Vol 18 (6) ◽  
pp. 615 ◽  
Author(s):  
RE Guthrie ◽  
KD Mclachlan ◽  
DGD Marco

Procedures for the partial purification of two phosphatase isozymes found in phosphorus deficient wheat plants are given. The method employs ammonium sulfate precipitation and hydroxylapatite, Con A-Sepharose, anion exchange and size exclusion chromatography. Measurements of their Km, Vmax, pI and molecular weight are reported. Evidence is provided that there are empirical differences in substrate utilisation between these phosphatase isozymes associated with phosphorus deficient plants.


2002 ◽  
Vol 80 (8) ◽  
pp. 900-903 ◽  
Author(s):  
Hong-Ni Fan ◽  
Mei-Zheng Liu ◽  
Yuan C Lee

An efficient and inexpensive method for large-scale preparation of α-D-(1[Formula: see text]4)-oligogalacturonic acids (oligo-GalA), up to DP 5, from pectic acid is described. Pectic acid was digested with a commercially available pectinase to yield a mixture of oligo-GalA, which was effectively separated by a combination of low-pressure – size-exclusion chromatography based on ion-exchange chromatography to obtain pure oligo-GalA of DP 2-5. Key words: pectic acid, galacturonic acid, galabiose, galatriose, pectinase.


1985 ◽  
Vol 31 (8) ◽  
pp. 670-674 ◽  
Author(s):  
William M. Fogarty ◽  
Catherine T. Kelly ◽  
Sunil K. Kadam

A novel α-glucosidase and a maltase were isolated from Bacillus amyloliquefaciens. The formation of both enzymes was induced by trehalose, sucrose, or lactose in the growth medium. Trehalose is by far the most efficient inducer of both systems. The α-glucosidase and maltase were separated and purified by ion-exchange chromatography on DEAE Bio-Gel A. Purified α-glucosidase hydrolysed p-nitrophenyl-α-D-glucoside, isomaltose, and isomaltotriose but sucrose, maltose, or related saccharides were not attacked. β-Glucosides and polymeric glucosides were not degraded. The optimum temperature for α-glucosidase activity was 40 °C and its pH optimum was 5.3. The molecular weight and isoelectric point (pI) of the enzyme were 27 000 and 4.6, respectively. Purified maltase attacked maltose and sucrose, while maltotriose and melezitose were hydrolysed at slower rates and p-nitrophenyl-α-D-glucoside was not degraded. Other properties of the maltase were as follows: optimum temperature for activity, 30 °C; pH optimum, 6.5; molecular weight, 64 000; and pI, 4.7.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Xiangmei Wu ◽  
Andrew Mort

A commercial apple pectin was sequentially digested with the cloned enzymes endopolygalacturonase, galactanase, arabinofuranosidase, xylogalacturonase, and rhamnogalacturonan hydrolase. The rhamnogalacturonan hydrolase-generated oligosaccharides were separated by ultrafiltration, anion exchange, and size-exclusion chromatography. Fractions from the ion exchange chromatography were pooled, lyophilized, and screened by MALDI-TOF MS. An oligosaccharide (RGP14P3) was identified and its structure, α-D-GalpA-(1→2)-α-L-Rhap-(1→4)-α-D-GalpA-(1→2)-α-L-Rhap-(1→4)-α-D-GalpA, determined by 1D and 2D NMR spectrometry. This oligosaccharide probably represents a direct connection between homogalacturonan and rhamnogalacturonan in pectin. Alternatively, it could indicate that the nonreducing end of rhamnogalacturonan starts with a galacturonic acid residue.


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