Properties of poly(ADP-ribose) synthetase from rat pancreas and poly(ADP-ribosylation) of basic nuclear proteins

The isolated nuclei of rat pancreas contain an enzyme system that will incorporate 3H-labeled NAD into an acid-insoluble product, which is shown to be poly(ADP-ribose). The enzyme has an optimum pH of 7.8 and the optimum temperature is between 20 and 30 °C. Optimum Mg2+ concentration is 8 mM and dithiothreitol also stimulates the enzyme at a concentration of 8 mM. Under standard conditions, the Km value for the reaction is 0.25 mM and an inhibition by the substrate is observed at high substrate concentrations. It has also been found that only one basic nuclear protein, that is, histone H1, is modified by the synthetase. An average chain length of 5.0 is found in the nuclei and of 4.5 on histone H1. Radioautographic studies show that poly(ADP-ribose) is closely associated with chromatin.

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Occurrence and Some Characterization Studies of Invertase in the Green Plantain Fruit (Musa parasidiaca)

The Journal of Agriculture of the University of Puerto Rico ◽

10.46429/jaupr.v46i2.12306 ◽

1969 ◽

Vol 46 (2) ◽

pp. 120-126

Author(s):

Betty G. García

Keyword(s):

Crude Protein ◽

Reaction Rate ◽

Order Reaction ◽

Zero Order ◽

Optimum Temperature ◽

First Order ◽

Sucrose Solutions ◽

Optimum Ph ◽

Characterization Studies ◽

Substrate Concentrations

The crude-protein fraction of green plantains was isolated and found to cause an inversion of sucrose solutions. The rate of inversion of sucrose by the invertase of the green plantain is proportional to the concentration of enzyme. The inversion of sucrose, when catalyzed by green-plantain invertase, appears to follow a first-order reaction rate at low substrate concentrations (below 6 percent). As the concentration of sucrose exceeds 6 percent the rate of the reaction changes to zero order. An optimum pH of 4.15 and an optimum temperature of 44.4° C. were obtained for the activity of green-plantain invertase.

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Poly(adenosine diphosphate ribose) polymerase in Physarum polycephalum

Biochemical Journal ◽

10.1042/bj1470119 ◽

1975 ◽

Vol 147 (1) ◽

pp. 119-129 ◽

Cited By ~ 51

Author(s):

M D Brightwell ◽

C E Leech ◽

M K O'Farrell ◽

W J Whish ◽

S Shall

Keyword(s):

Physarum Polycephalum ◽

Physiological Function ◽

Enzyme System ◽

Adenosine Diphosphate ◽

S Phase ◽

Optimum Conditions ◽

Exogenous Dna ◽

Optimum Ph ◽

Km Value ◽

Insoluble Product

1. The isolated nuclei of the slime mould Physarum polycephalum contain an enzyme that will incorporated [adenine-3H] NAD+ into an acid-insoluble product, which is shown to be poly(ADP-ribose). 2. This incorporation has an optimum pH of 8.2 and a temperature optimum below 10degreesC. 3. Optimum stimulation is given by 15 mM-Mg2+. 4. 2-Mercaptoethanol or dithiothreitol also stimulates the incorporation, the latter at an optimum concentration of about 1 mM. 5. Under optimum conditions the Km value for the reaction is 0.28 mM at 15degreesC. Nicotinamide inhibits the incorporation with a Ki of 5.7 muM. 6. Exogenous DNA stimulates the incorporation by about 100%. 7. Preincubation of the nuclei with deoxyribonuclease, but not with ribonuclease, almost completely inactivates the incorporation of NAD+. 8. The enzyme is unstable at both 0degrees and 15degreesC in the absence of dithiothreitol. The presence of dithiothreitol at a concentration of 1 mM stabilizes the enzyme at both these temperatures. 9. The activity of this enzyme per nucleus was shown in three separate experiments to fall by about one-half in early S phase and then to rise to its pre-mitotic value after about 3 h, that is in late S phase. 10. The possible physiological function of this enzyme system is discussed.

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Promising Pathway of Thermostable Mannitol Dehydrogenase (MtDH) from Caldicellulosiruptor hydrothermalis 108 for D-Mannitol Synthesis

Separations ◽

10.3390/separations8060076 ◽

2021 ◽

Vol 8 (6) ◽

pp. 76

Author(s):

Marwa Y. F. Koko ◽

Rokayya Sami ◽

Bertrand Muhoza ◽

Ebtihal Khojah ◽

Ahmed M. A. Mansour

Keyword(s):

Escherichia Coli ◽

Formate Dehydrogenase ◽

Enzyme System ◽

Catalytic Efficiency ◽

Optimum Temperature ◽

Initial Activity ◽

Mannitol Dehydrogenase ◽

Whole Cells ◽

Optimum Ph ◽

Molecular Masses

In this study, we conducted the characterization and purification of the thermostable mannitol dehydrogenase (MtDH) from Caldicellulosiruptor hydrothermalis 108. Furthermore, a coupling-enzyme system was designed using (MtDH) from Caldicellulosiruptor hydrothermalis 108 and formate dehydrogenase (FDH) from Ogataea parapolymorpha. The biotransformation system was constructed using Escherichia coli whole cells. The purified enzyme native and subunit molecular masses were 76.7 and 38 kDa, respectively, demonstrating that the enzyme was a dimer. The purified and couple enzyme system results were as follows; the optimum pH for the reduction and the oxidation was 7.0 and 8.0, the optimum temperature was 60 °C, the enzyme activity was inhibited by EDTA and restored by zinc. Additionally, no activity was detected with NADPH and NADP. The purified enzyme showed high catalytic efficiency Kcat 385 s−1, Km 31.8 mM, and kcat/Km 12.1 mM−1 s−1 for D-fructose reduction. Moreover, the purified enzyme retained 80%, 75%, 60%, and 10% of its initial activity after 4 h at 55, 60, 65, and 75 °C, respectively. D-mannitol yield was achieved via HPLC. Escherichia coli are the efficient biotransformation mediator to produce D-mannitol (byproducts free) at high temperature and staple pH, resulting in a significant D-mannitol conversation (41 mg/mL) from 5% D-fructose.

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Production of N-acetylglucosamine from shrimp shells’ chitin using intracellular chitinase from Mucor circinelloides

Food Research ◽

10.26656/fr.2017.4(5).135 ◽

2020 ◽

Vol 4 (5) ◽

pp. 1582-1587

Author(s):

Yuniwaty Halim ◽

Fransiska ◽

Hardoko ◽

R. Handayani

Keyword(s):

Incubation Period ◽

Substrate Concentration ◽

Chitinase Activity ◽

Mucor Circinelloides ◽

Optimum Temperature ◽

Shrimp Shells ◽

Incubation Periods ◽

Optimum Ph ◽

Substrate Concentrations ◽

Optimum Ph And Temperature

Chitin is a natural biopolymer found in shrimp shells and can be processed into Nacetylglucosamine which is extensively used as a dietary supplement to treat osteoarthritis, back pain and knee pain. This research was conducted to determine the optimum pH, temperature, substrate concentration and incubation period to produce Nacetylglucosamine using crude and semi pure intracellular chitinase extracted from Mucor circinelloides. Chitinase activity was measured to determine optimum pH and temperature by using various pHs (3, 4, 5, 6, 7, 8 and 9) and temperatures (30oC, 40oC, 50oC, 60oC, 70oC and 80oC). Different substrate concentrations (0.5%, 1.0%, 1.5% and 2.0%) and incubation periods (2, 4, 6 and 24 hrs) were used to determine the optimum condition to produce N-acetylglucosamine. Results showed that crude intracellular chitinase had an optimum pH of 5 with chitinase activity of 4.16±0.07 U/mL and optimum temperature of 60oC with chitinase activity of 4.22±0.07 U/mL. The optimum substrate concentration obtained was 0.5% and the optimum incubation period obtained was 6 hrs with about 961.67±9.13 ppm N-acetylglucosamine produced. Semi pure intracellular chitinase had an optimum pH of 4 with chitinase activity of 4.75±0.09 U/mL and optimum temperature of 50oC with chitinase activity of 5.03±0.08 U/mL. The optimum substrate concentration obtained was 1.5% and the optimum incubation period obtained was 4 hrs with about 1150.56±12.55 ppm N-acetylglucosamine produced.

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Immobilization and Characterization of Tannase and its Haze-removing

Food Science and Technology International ◽

10.1177/1082013209352919 ◽

2009 ◽

Vol 15 (6) ◽

pp. 545-552 ◽

Cited By ~ 9

Author(s):

Erzheng Su ◽

Tao Xia ◽

Liping Gao ◽

Qianying Dai ◽

Zhengzhu Zhang

Keyword(s):

Kinetic Parameter ◽

High Activity ◽

Green Tea ◽

Storage Stability ◽

Residual Activity ◽

Black Tea ◽

Optimum Temperature ◽

Oolong Tea ◽

Optimum Ph

Tannase was effectively immobilized on alginate by the method of crosslinking-entrapment-crosslinking with a high activity recovery of 76.6%. The properties of immobilized tannase were investigated. Its optimum temperature was determined to be 35 ° C, decreasing 10 °C compared with that of free enzyme, whereas the optimum pH of 5.0 did not change. The thermal and pH stabilities of immobilized tannase increased to some degree. The kinetic parameter, Km, for immobilized tannase was estimated to be 11.6 × 10-4 mol/L. Fe2+ and Mn2+ could activate the activity of immobilized tannase. The immobilized tannase was also applied to treat the tea beverage to investigate its haze-removing effect. The content of non-estern catechins in green tea, black tea and oolong tea increased by 52.17%, 12.94% and 8.83%, respectively. The content of estern catechins in green tea, oolong tea and black tea decreased by 20.0%, 16.68% and 5.04%, respectively. The anti-sediment effect of green tea infusion treated with immobilized tannase was significantly increased. The storage stability and reusability of the immobilized tannase were improved greatly, with 72.5% activity retention after stored for 42 days and 86.9% residual activity after repeatedly used for 30 times.

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

Revista de Microbiologia ◽

10.1590/s0001-37141999000300014 ◽

1999 ◽

Vol 30 (3) ◽

pp. 265-271 ◽

Cited By ~ 5

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

b-Galactosidase or b-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 b-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.

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Characterization of Biosynthetic Enzymes for Ectoine as a Compatible Solute in a Moderately Halophilic Eubacterium, Halomonas elongata

Journal of Bacteriology ◽

10.1128/jb.181.1.91-99.1999 ◽

1999 ◽

Vol 181 (1) ◽

pp. 91-99 ◽

Cited By ~ 111

Author(s):

Hisayo Ono ◽

Kazuhisa Sawada ◽

Nonpanga Khunajakr ◽

Tao Tao ◽

Mihoko Yamamoto ◽

...

Keyword(s):

Molecular Mass ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Gel Filtration ◽

Apparent Molecular Mass ◽

Optimum Temperature ◽

Sds Page ◽

Halomonas Elongata ◽

Optimum Ph

ABSTRACT 1,4,5,6-Tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (ectoine) is an excellent osmoprotectant. The biosynthetic pathway of ectoine from aspartic β-semialdehyde (ASA), in Halomonas elongata, was elucidated by purification and characterization of each enzyme involved. 2,4-Diaminobutyrate (DABA) aminotransferase catalyzed reversively the first step of the pathway, conversion of ASA to DABA by transamination with l-glutamate. This enzyme required pyridoxal 5′-phosphate and potassium ions for its activity and stability. The gel filtration estimated an apparent molecular mass of 260 kDa, whereas molecular mass measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was 44 kDa. This enzyme exhibited an optimum pH of 8.6 and an optimum temperature of 25°C and had Km s of 9.1 mM forl-glutamate and 4.5 mM for dl-ASA. DABA acetyltransferase catalyzed acetylation of DABA to γ-N-acetyl-α,γ-diaminobutyric acid (ADABA) with acetyl coenzyme A and exhibited an optimum pH of 8.2 and an optimum temperature of 20°C in the presence of 0.4 M NaCl. The molecular mass was 45 kDa by gel filtration. Ectoine synthase catalyzed circularization of ADABA to ectoine and exhibited an optimum pH of 8.5 to 9.0 and an optimum temperature of 15°C in the presence of 0.5 M NaCl. This enzyme had an apparent molecular mass of 19 kDa by SDS-PAGE and a Km of 8.4 mM in the presence of 0.77 M NaCl. DABA acetyltransferase and ectoine synthase were stabilized in the presence of NaCl (>2 M) and DABA (100 mM) at temperatures below 30°C.

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Immobilization of Isolated Lipase From Moldy Copra(Aspergillus Oryzae)

E-Journal of Chemistry ◽

10.1155/2011/608075 ◽

2011 ◽

Vol 8 (2) ◽

pp. 896-902

Author(s):

Seniwati Dali ◽

A. B. D. Rauf Patong ◽

M. Noor Jalaluddin ◽

Pirman ◽

Baharuddin Hamzah

Keyword(s):

Thermal Stability ◽

Aspergillus Oryzae ◽

Immobilized Lipase ◽

Optimum Temperature ◽

Adsorption Method ◽

Ph Optimum ◽

Optimum Ph ◽

Recovery Technique ◽

Free Lipase

Enzyme immobilization is a recovery technique that has been studied in several years, using support as a media to help enzyme dissolutions to the reaction substrate. Immobilization method used in this study was adsorption method, using specific lipase fromAspergillus oryzae. Lipase was partially purified from the culture supernatant ofAspergillus oryzae. Enzyme was immobilized by adsorbed on silica gel. Studies on free and immobilized lipase systems for determination of optimum pH, optimum temperature, thermal stability and reusability were carried out. The results showed that free lipase had optimum pH 8,2 and optimum temperature 35 °C while the immobilized lipase had optimum 8,2 and optimum temperature 45 °C. The thermal stability of the immobilized lipase, relative to that of the free lipase, was markedly increased. The immobilized lipase can be reused for at least six times.

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Preparation of Cross-Linked Enzyme Aggregates (CLEAs) of an Inulosucrase Mutant for the Enzymatic Synthesis of Inulin-Type Fructooligosaccharides

Catalysts ◽

10.3390/catal9080641 ◽

2019 ◽

Vol 9 (8) ◽

pp. 641 ◽

Cited By ~ 2

Author(s):

Thanapon Charoenwongpaiboon ◽

Rath Pichyangkura ◽

Robert A. Field ◽

Manchumas Hengsakul Prousoontorn

Keyword(s):

Enzymatic Synthesis ◽

Biochemical Characterization ◽

Lactobacillus Reuteri ◽

Soluble Enzyme ◽

Optimum Temperature ◽

Optimum Conditions ◽

Product Specificity ◽

Product Characterization ◽

Optimum Ph ◽

Probiotic Activity

Fructooligosaccharides are well-known carbohydrate molecules that exhibit good probiotic activity and are widely used as sweeteners. Inulin-type fructooligosaccharides (IFOs) can be synthesized from sucrose using inulosucrase. In this study, cross-linked enzyme aggregates (CLEAs) of Lactobacillus reuteri 121 inulosucrase (R483A-LrInu) were prepared and used as a biocatalyst for IFOs production. Under optimum conditions, R483A-LrInu CLEAs retained 42% of original inulosucrase activity. Biochemical characterization demonstrated that the optimum pH of inulosucrase changed from 5 to 4 after immobilization, while the optimum temperature was unchanged. Furthermore, the pH stability and thermostability of the R483A-LrInu CLEAs was significantly improved. IFOs product characterization indicated that the product specificity of the enzyme was impacted by CLEA generation, producing a narrower range of IFOs than the soluble enzyme. In addition, the R483A-LrInu CLEAs showed operational stability in the batch synthesis of IFOs.

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