Purification and Properties of Ribonuclease From Buffalo Milk Whey

1977 ◽  
Vol 40 (6) ◽  
pp. 375-377 ◽  
Author(s):  
AZZA A. ISMAIL ◽  
N. S. AHMED ◽  
M. A. KHORSHID
Keyword(s):  
Deae Cellulose ◽  
Ribonuclease A ◽  
Buffalo Milk ◽  
Optimum Temperature ◽  
Isolation And Identification ◽  
Milk Whey ◽  
Purification And Properties ◽  
Optimum Ph ◽  
Ribonuclease B

A procedure was developed for isolation and identification of ribonuclease from buffalo milk whey. Ribonuclease was precipitated with (NH4)2SO4 between 65 and 90% saturation. The precipitate was dissolved, dialyzed, and fractionated on DEAE-cellulose. Two ribonuclease-rich fractions were collected, i.e. ribonuclease A and B. Ribonuclease A had an optimum pH of 7 .0, and ribonuclease B had an optimum pH of 8.6. Both had an optimum temperature at 38 C. The ribonucleases in the purified state were unstable to heat and their activity decreased as the time of exposure increased. Both enzyme fractions were sensitive to inhibitors. NaCl and NaN3 were stimulatory for ribonuclease A, while ribonuclease B was stimulated only by NaCl.

scholarly journals Properties of a new fungal b-galactosidase with potential application in the dairy industry

1999 ◽  
Vol 30 (3) ◽  
pp. 265-271 ◽  
Author(s):  
Rubens Cruz ◽  
Vinícius D'Arcádia Cruz ◽  
Juliana Gisele Belote ◽  
Marcelo de Oliveira Khenayfes ◽  
Claudia Dorta ◽  
...  
Keyword(s):  
Hydrolytic Activity ◽  
Industrial Applications ◽  
Transferase Activity ◽  
Optimum Temperature ◽  
Milk Whey ◽  
Beneficial Effects ◽  
Optimum Ph ◽  
Semi Solid ◽  
Good Productivity ◽  
Hydrolysis Of

<FONT FACE="Symbol">b</font>-Galactosidase or <FONT FACE="Symbol">b</font>-D-galactoside-galactohydrolase (EC. 3.2.1.23) is an important enzyme industrially used for the hydrolysis of lactose from milk and milk whey for several applications. Lately, the importance of this enzyme was enhanced by its galactosyltransferase activity, which is responsible for the synthesis of transgalactosylated oligosaccharides (TOS) that act as functional foods, with several beneficial effects on consumers. Penicillium simplicissimum, a strain isolated from soil, when grown in semi-solid medium showed good productivity of <FONT FACE="Symbol">b</font>-galactosidase with galactosyltransferase activity. The optimum pH for hydrolysis was in the 4.04.6 range and the optimum pH for galactosyltransferase activity was in the 6.07.0 range. The optimum temperature for hydrolysis and transferase activity was 55-60°C and 50°C, respectively, and the enzyme showed high thermostability for the hydrolytic activity. The enzyme showed a potential for several industrial applications such as removal of 67% of the lactose from milk and 84% of the lactose from milk whey when incubated at their original pH (4.5 and 6.34, respectively) under optimum temperature conditions. When incubated with a 40% lactose solution in 150 mM McIlvaine buffer, pH 4.5, at 55°C the enzyme converted 86.5% of the lactose to its component monosaccharides. When incubated with a 60% lactose solution in the same buffer but at pH 6.5 and 50°C, the enzyme can synthetize up to 30.5% TOS, with 39.5% lactose and 30% monosaccharides remaining in the preparation.

A fundamental thermostable cyanide-sensitive phosphoenolpyruvate acid carboxylase in photosynthetic and other organisms

1971 ◽  
Vol 49 (4) ◽  
pp. 631-643 ◽  
Author(s):  
David Pan ◽  
E. Roy Waygood
Keyword(s):  
Heat Treatment ◽  
Zea Mays ◽  
Acid Phosphatase ◽  
Plant Species ◽  
Phosphoenolpyruvate Carboxylase ◽  
Deae Cellulose ◽  
Bundle Sheath ◽  
Evolutionary Significance ◽  
Optimum Temperature ◽  
Optimum Ph

A thermostable 'phosphoenolpyruvate carboxylase' has been isolated from leaves of Zea mays different from phosphoenolpyruvate carboxylase (EC. 4.1.1.31) in that its optimum pH is 5.4, it does not liberate orthophosphate during the reaction, and it is inhibited by cyanide. The enzymic reaction has an optimum temperature of 70–75C and has been purified through steps including acidification to pH 4.6, heat treatment to 50C, and DEAE-cellulose and Sephadex G-200 column chromatography. Three fractions were active in the Sephadex eluate, but only fraction III was free from a thermostable acid phosphatase which catalyzes the liberation of orthophosphate from the substrate and the end product which is suggested to be a C4 phosphocarbonyl compound, although phosphohydroxypyruvate appears by either spontaneous or enzymic decarboxylation. The enzyme is assayed by the formation of a phenyl-hydrazone at 325 nm. The enzyme is localized and tightly bound in both the parenchyma bundle sheath and mesophyll chloroplasts, which are free from the thermostable acid phosphatase. Similar concentrations of the enzyme have been found in all plant species tested including C3 plants, ferns, bryophytes, algae, fungi, and even in calf liver. The enzyme must have considerable evolutionary significance.

Isolation and Identification of Strains with High Chitin Deacetylase Activity

2012 ◽  
Vol 457-458 ◽  
pp. 476-479
Author(s):  
Jing Xuan Gou ◽  
Wen Bin Dong ◽  
Qiao Zeng ◽  
Jing Jing Zhang
Keyword(s):  
Food Industry ◽  
Analysis Data ◽  
Soil Samples ◽  
Optimum Temperature ◽  
Isolation And Identification ◽  
Chitin Deacetylase ◽  
Physiological And Biochemical Characteristics ◽  
Optimum Ph ◽  
Physiological And Biochemical ◽  
Rdna Analysis

Chitosan is an aboundant biopolymer like cellose. To bioprocess them with chitin deacetylase (CDA), the products will be used in medicine and food industry. [In order to get new strains with significant ability of (CDA) Twenty eight strains producing CDA were isolated and screened out from the soil samples by color reaction in plate medium. The strain F2-7-3 was screened out from these strains for the highest CDA activity, which can reach more than 250U/mL. The paranitroacetanilide was used as the substrate, the optimum temperature for enzyme activity was determined to be 50°C and the optimum pH was 7.0. It was studied by method of morphological, physiological and biochemical characteristics and 16S rDNA analysis. Data shows that the strain was Rhodococcus sp.

scholarly journals A Study of Glutathione S-Aryltransferase from Costelytra Zealandica

2021 ◽  
Author(s):  
◽  
Graeme Lyall Dick
Keyword(s):  
Deae Cellulose ◽  
Effect Of Temperature ◽  
Endogenous Inhibitor ◽  
Catalysed Reaction ◽  
Purification And Properties ◽  
Isoelectric Points ◽  
Costelytra Zealandica ◽  
Optimum Ph ◽  
Effects Of Ph ◽  
The Stability

<p>An investigation has been made of the stability, purification and properties of Glutathione S-aryltransferase (Ec 2.5.1.13) from the grass-grub, Costelytra zealandica. The enzyme was found to be extremely unstable in crude homogenates of grass-grubs that had been stored frozen at -2O degrees C, but was considerably more stable in homogenates of live grass-grubs. The instability increased with increase of pH. Glutathione gave some protection against inactivation. Selective fractionation of crude homogenates with (NH4)2SO4 provided some evidence for the presence of an endogenous inhibitor of the enzyme. DEAE-cellulose chromatography and isoelectric focusing studies showed the presence of two major GSH S-aryltransferases with isoelectric points of 4.6 and 8.7. Both enzymes were present in the homogenate from a single, live, grass-grub. The molecular weight and optimum pH of each enzyme was identical within experimental error. A brief comparative study of GSH S-transferases showed the presence of GSH S-alkyl- and GSH s-alkene-transferase, but in only very small amounts compared with GSH S-aryltransferase. Differences in stability were demonstrated and some cross-specificity was indicated. Several inhibitor-substituted Sepharoses were prepared in an attempt to purify GSH s-aryltransferase by affinity chromatography. Although columns of the inhibitors removed the enzyme from solution an active enzyme could not be recovered. The effects of pH and temperature on the enzyme-catalysed reaction of GSH and 1, 2-dichloro-4-nitrobenzene (DCNB) were investigated in detail. Analysis of the variation of pKGSH with pH showed the presence of active site groups with pK approximately 9 involved in GSH binding. Calculation of the heat of ionization of these groups in the pI 8.7 enzyme, from the effect of temperature on their pK, suggested that the groups may be Lysine epsilon-NH2. Values for the enthalpy, free energy and entropy of GSH-binding to the pI 8.7 enzyme and of DCNB-binding to the enzyme-GSH complex were also obtained.</p>

Purification and properties of an exocellular β-glucosidase of Candida molischiana (Zikes) Meyer and Yarrow capable of hydrolyzing soluble cellodextrins

1985 ◽  
Vol 63 (11) ◽  
pp. 1160-1166 ◽  
Author(s):  
Pierre Gondé ◽  
Robert Ratomahenina ◽  
Alain Arnaud ◽  
Pierre Galzy
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Optimum Temperature ◽  
Purification And Properties ◽  
Optimum Ph

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.

scholarly journals Purification of NADP-Isocitrate dehydrogenase from Red Kidney beans (Phaseolus vulgaris rogue)

2010 ◽  
Vol 4 (1) ◽  
pp. 61-72
Author(s):  
Mukaram Shikara ◽  
Hiba Muneer Al-Khafagi ◽  
Wasnaa H. Faris
Keyword(s):  
Phaseolus Vulgaris ◽  
Isocitrate Dehydrogenase ◽  
Deae Cellulose ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Optimum Temperature ◽  
Ammonium Sulphate Precipitation ◽  
Kidney Beans ◽  
Optimum Ph ◽  
Murashige Skoog ◽  
Red Kidney Beans

Nicotinamide adenine dinucleotide phosphate-dependent isocitrate dehydrogenase (NADP+-IDH; EC 1.1.1.42) was extracted from red kidney beans (Phaseolus vulgaris.) after the beans were placed into Murashige-Skoog medium and incubated under continuous white light (110 μmol photon m−2 s−1), then filtered, centrifuged and the supernatant was used for purification. The enzyme purified using ammonium sulphate precipitation, DEAE-cellulose and Matrex Bio red A (dye-ligand-chromatography) techniques, and exhibits several bands through electrophoresis, with one band corresponds to the IDH activity. Km values for the enzyme was 55.71± 4.56 x 10-6M. The enzyme has an optimum pH at 8.5, and optimum temperature at 30°C. The enzyme can be stable at RT (about 25°C) for 180min, but the activity disappears at 400min. Enzyme activity appears to be independent of divalent metals in deionized water, but the addition of Mg+2 and Mn+2 by 4.5 and 2-folds respectively. The purified enzyme was injected into white rabbits to raise an antiserum against NADP+-IDH. The specificity of the antiserum was assayed by its ability to decrease the NADP+-IDH activity present in the extract. NADP+-IDH activity decreased when the extract was incubated with increasing volumes of the antiserum obtained.

An extracellular proteolytic enzyme from Scopulariopsis brevicaulis. 1. Purification and properties

1971 ◽  
Vol 17 (8) ◽  
pp. 1029-1042 ◽  
Author(s):  
Kartar Singh ◽  
Claude Vézina
Keyword(s):  
Proteolytic Enzyme ◽  
Deae Cellulose ◽  
Alkaline Proteases ◽  
Casein Hydrolysis ◽  
Purification And Properties ◽  
Optimum Ph ◽  
Sh Reagents ◽  
Extracellular Proteolytic Enzyme ◽  
Scopulariopsis Brevicaulis ◽  
Insulin Chains

A proteolytic enzyme present in culture filtrates of Scopulariopsis brevicaulis was purified about 200-fold by (NH4)2SO4 and ethanol fractionations followed by chromatography on DEAE-cellulose, DEAE-Sephadex, and hydroxylapatite. Ultracentrifugation of the purified enzymes showed only one sedimenting component and its molecular weight was estimated to be about 24 000. The protease hydrolyzed casein, urea-denatured hemoglobin, gelatin, fibrinogen, fibrin, insulin chains A and B, but not human serum albumin or ovalbumin. It also coagulated milk. The enzyme had no action on the various peptides tested and showed low esterase activity. Optimum pH for casein hydrolysis was 10.5 to 11; for hemoglobin hydrolysis 7.0–9.5, and for gelatin hydrolysis, 6.0–8.0. The enzyme activity was unaffected by most metal ions, SH-reagents, and some natural trypsin inhibitors. The protease was strongly inhibited by diisopropylfluorophosphate and phenylmethanesulfonyl fluoride. Although similar in some respects to CA-7, the enzyme isolated from Aspergillus oryzae, and other alkaline proteases, the S. brevicaulis protease does not appear to be identical with any one of them.

scholarly journals A Study of Glutathione S-Aryltransferase from Costelytra Zealandica

2021 ◽  
Author(s):  
◽  
Graeme Lyall Dick
Keyword(s):  
Deae Cellulose ◽  
Effect Of Temperature ◽  
Endogenous Inhibitor ◽  
Catalysed Reaction ◽  
Purification And Properties ◽  
Isoelectric Points ◽  
Costelytra Zealandica ◽  
Optimum Ph ◽  
Effects Of Ph ◽  
The Stability

<p>An investigation has been made of the stability, purification and properties of Glutathione S-aryltransferase (Ec 2.5.1.13) from the grass-grub, Costelytra zealandica. The enzyme was found to be extremely unstable in crude homogenates of grass-grubs that had been stored frozen at -2O degrees C, but was considerably more stable in homogenates of live grass-grubs. The instability increased with increase of pH. Glutathione gave some protection against inactivation. Selective fractionation of crude homogenates with (NH4)2SO4 provided some evidence for the presence of an endogenous inhibitor of the enzyme. DEAE-cellulose chromatography and isoelectric focusing studies showed the presence of two major GSH S-aryltransferases with isoelectric points of 4.6 and 8.7. Both enzymes were present in the homogenate from a single, live, grass-grub. The molecular weight and optimum pH of each enzyme was identical within experimental error. A brief comparative study of GSH S-transferases showed the presence of GSH S-alkyl- and GSH s-alkene-transferase, but in only very small amounts compared with GSH S-aryltransferase. Differences in stability were demonstrated and some cross-specificity was indicated. Several inhibitor-substituted Sepharoses were prepared in an attempt to purify GSH s-aryltransferase by affinity chromatography. Although columns of the inhibitors removed the enzyme from solution an active enzyme could not be recovered. The effects of pH and temperature on the enzyme-catalysed reaction of GSH and 1, 2-dichloro-4-nitrobenzene (DCNB) were investigated in detail. Analysis of the variation of pKGSH with pH showed the presence of active site groups with pK approximately 9 involved in GSH binding. Calculation of the heat of ionization of these groups in the pI 8.7 enzyme, from the effect of temperature on their pK, suggested that the groups may be Lysine epsilon-NH2. Values for the enthalpy, free energy and entropy of GSH-binding to the pI 8.7 enzyme and of DCNB-binding to the enzyme-GSH complex were also obtained.</p>

Isolation and Identification of a Chitin Degrading Bacterium Aeromonas SP D5-23 and Properties of Chitinase

2012 ◽  
Vol 457-458 ◽  
pp. 472-475
Author(s):  
Jing Xuan Gou ◽  
Wen Bin Dong ◽  
Qiao Zeng ◽  
Lei Jin
Keyword(s):  
Enzyme Activity ◽  
Soil Sample ◽  
16S Rdna ◽  
Morphological Analysis ◽  
Chitinase Activity ◽  
Vibrio Alginolyticus ◽  
Optimum Temperature ◽  
Isolation And Identification ◽  
Degrading Bacterium ◽  
Optimum Ph

Chitin is an abundant biopolymer like cellulose that is rather resistant to degradation. In order to develop a bio-digesting method, soil sample in Qinling Mountain were collected for screening the bacteria with high chitinase activity by method of the transparent circle. The strain D5-23 was isolated and screened out from soil, which was found with amazing chitinase acitivity. The ratio of transient circle and colony circle is no less than 10. The strain was then identified as Aeromonas sp according to the sequences of 16S rDNA and morphological analysis. The enzyme activity was studied further, ,data shows that the optimum temperature was 45°C, which is similar to other Aeromonas sp, wheras the optimum pH is 5 and 9, which is more similar to Vibrio alginolyticus TK-22.

Purification and characterization of the extracellular amylases of the yeast Schwanniomyces alluvius

1984 ◽  
Vol 30 (9) ◽  
pp. 1163-1170 ◽  
Author(s):  
B. Simões-Mendes
Keyword(s):  
Deae Cellulose ◽  
Culture Fluid ◽  
Soluble Starch ◽  
Ph Stability ◽  
Starch Hydrolysis ◽  
Heat Inactivation ◽  
Optimum Temperature ◽  
Enzyme Preparations ◽  
Optimum Ph

The extracellular amylolytic system of a strain of the yeast Schwanniomyces alluvius consists of an α-amylase, a glucoamylase, and probably a debranching enzyme. Crude enzyme preparations were obtained by fractionation of the culture fluid, at the stationary phase of growth, with isopropanol. Purification was carried out by DEAE-cellulose chromatography. The glucoamylase had the following properties: molecular weight (MW), 117 000 ± 2300; optimum temperature, 50 °C; optimum pH, 4.5; range of pH stability, pH 4–6; final product of starch hydrolysis, glucose; ΔH≠ and ΔS≠ of heat inactivation, 39747 cal∙mol−1 and 274.3 cal∙deg−1∙mo−1; Km(30 °C, pH 4.5) for soluble starch, 22.22 g∙L−1. The α-amylase had the following properties: MW, 62 000 ± 500; optimum temperature, 40 °C; optimum pH, 6.3; range of pH stability, pH 4–7; final product of starch hydrolysis, maltose and glucose; ΔH≠ and ΔS≠ of heat inactivation, 36594 cal∙mol−1 and 256.9 cal∙deg−1 mol−1; Km (40 °C, pH 5.5), 2.7 g∙L−1.

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