scholarly journals CHARACTERIZATION OF CRUDE EXTRACT POLYPHENOLOXIDASE ENZYME FROM BLACK TIGER SHRIMP (Penaeus monodon)

2013 ◽  
Vol 5 (2) ◽  
Author(s):  
Made Suhandana ◽  
Tati Nurhayati ◽  
Laksmi Ambarsari
Keyword(s):  
Enzyme Activity ◽  
Metal Ion ◽  
Penaeus Monodon ◽  
Extraction Condition ◽  
Ph Optimum ◽  
Km Value ◽  
Shrimp Industry ◽  
Optimum Extraction ◽  
Inhibited Enzyme

Shrimp is a  very important export  commodity with  high market value world wide. However, it is still facing problem related to the waste and deterioration quality as main issues for the shrimp industry. In this experiment, polyphenoloxidase from the carapace of Penaeus monodon was extracted and characterized. The research was carried out to obtain the optimum extraction condition and to evaluate the properties of enzyme i.e., pH, optimum temperature for activating enzyme, kinetic enzyme, and chelating on metal ion. The best method for PPO enzyme extraction used buffer with 1:3  proportion.  The optimum activity of enzyme was at pH 7 and temperature of 35°C. The kinematic enzyme (Km) value and the maximum substrate concentration were 5.42 mM and 7.5 mM, respectively.  Na+, Ca2+, Zn2+, and EDTA with concentration 5 and 10 mM inhibited enzyme activity.  Cu2+at concentration of 10 mM and Mn2+ at concentration 5 mM also inhibited enzyme activity Keywords: carapace, characterization, polyphenoloxidase, shrimp

scholarly journals CHARACTERIZATION OF CRUDE EXTRACT POLYPHENOLOXIDASE ENZYME FROM BLACK TIGER SHRIMP (Penaeus monodon)

2013 ◽  
Vol 5 (2) ◽  
Author(s):  
Made Suhandana ◽  
Tati Nurhayati ◽  
Laksmi Ambarsari
Keyword(s):  
Enzyme Activity ◽  
Metal Ion ◽  
Penaeus Monodon ◽  
Extraction Condition ◽  
Ph Optimum ◽  
Km Value ◽  
Shrimp Industry ◽  
Optimum Extraction ◽  
Inhibited Enzyme

<p>Shrimp is a  very important export  commodity with  high market value world wide. However, it is still facing problem related to the waste and deterioration quality as main issues for the shrimp industry. In this experiment, polyphenoloxidase from the carapace of Penaeus monodon was extracted and characterized. The research was carried out to obtain the optimum extraction condition and to evaluate the properties of enzyme i.e., pH, optimum temperature for activating enzyme, kinetic enzyme, and chelating on metal ion. The best method for PPO enzyme extraction used buffer with 1:3  proportion.  The optimum activity of enzyme was at pH 7 and temperature of 35°C. The kinematic enzyme (Km) value and the maximum substrate concentration were 5.42 mM and 7.5 mM, respectively.  Na<sup>+</sup>, Ca<sup>2+</sup>, Zn<sup>2+</sup>, and EDTA with concentration 5 and 10 mM inhibited enzyme activity.  Cu<sup>2+</sup>at concentration of 10 mM and Mn<sup>2+</sup> at concentration 5 mM also inhibited enzyme activity</p> <p>Keywords: carapace, characterization, polyphenoloxidase, shrimp</p>

Characterization of an octopamine-sensitive adenylate cyclase from insect brain (Mamestra configurata Wlk.)5

1979 ◽  
Vol 57 (3) ◽  
pp. 226-232 ◽  
Author(s):  
Robert P. Bodnaryk
Keyword(s):  
Enzyme Activity ◽  
Adenylate Cyclase ◽  
Metal Ion ◽  
Cyclase Activity ◽  
Mammalian Brain ◽  
Insect Brain ◽  
Ph Optimum ◽  
Mamestra Configurata ◽  
Specificity Effect

An adenylate cyclase present in the brain of the moth Mamestra configurata Wlk. that is stimulated selectively by low (micromolar) concentrations of octopamine has been characterized with respect to several properties. The optimum pH, optimum ATP:Mg2+ ratio, the concentration of ATP required for half-maximal and maximal reaction velocity, metal ion specificity, effect of NaF, and effects of GTP and 5′-guanylylimidodiphosphate were in general similar to those of catecholamine-sensitive adenylate cyclases from various regions of mammalian brain. However, ethylene glycol bis-(β-aminoethyl ether)-N,N-tetraacetic acid (EGTA), a calcium chelator, stimulated both basal and octopamine-sensitive enzyme activity in the insect brain, whereas in mammalian brain EGTA is usually observed to inhibit basal activity but not catecholamine-stimulated activity.Adenylate cyclase activity of the 47 000 g particulate fraction of the insect brain was almost undetectable in the absence of added GTP. Addition of saturating concentrations (100 μM) of GTP to the particles restored about 30% of the basal and octopamine-sensitive enzyme activity present in the homogenate. Addition of 100 000 g supernatant to the particles doubled both basal and octopamine-sensitive enzyme activity in the presence of saturating concentrations of GTP, indicating that in addition to GTP, a cytosolic factor(s) is necessary for enhanced adenylate cyclase activity.

Characterization of α-Farnesene Synthase from `Delicious' Apples

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 532d-532
Author(s):  
H.P.V. Rupasinghe ◽  
G. Paliyath ◽  
D.P. Murr
Keyword(s):  
Enzyme Activity ◽  
Metal Ion ◽  
Divalent Metal ◽  
Farnesyl Pyrophosphate ◽  
Anaerobic Conditions ◽  
Ph Optimum ◽  
Divalent Metal Ion ◽  
Apple Cultivars ◽  
Inherent Nature

α-Farnesene metabolism is associated with the occurrence of superficial scald in pome fruits. Trans,trans-α-farnesene synthase, which catalyzes the terminal step of α-farnesene biosynthesis viz. conversion of farnesyl pyrophosphate to α-farnesene, has been characterized in the extract from skin tissues of `Delicious' apples (Malus domestica Borkh.). The total and specific activities of the enzyme were the highest in the cytosolic fraction when compared to that in membrane fractions. The enzyme possessed a pH optimum of 5.6 and required a divalent metal ion (Mg+2 and Mn+2 were preferred). The activity was highest between 10 and 20 °C, although 50 % of the activity was still retained at 0 °C. The presence of thiol reagents, pyridine dinucleotide effectors, anaerobic conditions or antioxidants did not significantly affect enzyme activity. α-Farnesene synthase activity was similar in the extract of skin tissue from scald-developing and non-scald-developing apples. The enzyme activity was not correlated to the inherent nature of scald-susceptibility or resistance in eight different apple cultivars tested.

Sinapine Esterase I. Characterization of Sinapine Esterase from Cotyledons of Raphanus sativus

1979 ◽  
Vol 34 (9-10) ◽  
pp. 715-720 ◽  
Author(s):  
Gerhild Nurmann ◽  
Dieter Strack
Keyword(s):  
Enzyme Activity ◽  
Esterase Activity ◽  
Raphanus Sativus ◽  
Sinapic Acid ◽  
Inhibitory Effect ◽  
Ph Optimum ◽  
Diisopropyl Fluorophosphate ◽  
E 600 ◽  
Red Radish

Abstract From cotyledons of Raphanus sativus (red radish) an esterase activity which catalyzes the hy­drolysis of sinapine into sinapic acid and choline has been isolated. The enzyme, which has a near absolute specificity, is not analogous with any esterase described in the literature. The reaction has a pH optimum of 8.5 and the apparent Km is 1.95 × 10-5 m. The enzyme is relatively insensi­tive to both physostigmine (eserine) {Ki = 1.73 × 10-4 m) and neostigmine (Ki = 2 .1 3 × 10-4 ᴍ). Diisopropyl fluorophosphate (DFP) showed no inhibition and diethyl p-nitrophenylphosphate (E 600) only a slight inhibitory effect at 10-5 ᴍ, respectively. Choline (10-2 ᴍ) was inhibitory but acetylcholine (10-2 ᴍ) stimulated the enzyme activity.

Isolation and Partial Characterization of Alcohol Dehydrogenase From Broad Bean (Vicia faba)

1974 ◽  
Vol 1 (4) ◽  
pp. 579 ◽  
Author(s):  
S Leblova
Keyword(s):  
Thermal Stability ◽  
Alcohol Dehydrogenase ◽  
Broad Bean ◽  
Plant Tissues ◽  
Growth Substances ◽  
Ph Optimum ◽  
Alcohol Dehydrogenase Activity ◽  
Km Value ◽  
Thermal Stability Of

Alcohol dehydrogenase isolated from broad bean was found to have a Km value of 1.0 × 1.0 -2 M, a pH optimum of 8.7 and a molecular weight of 60 000 � 5000. The enzyme lost 55 % of its activity after being heated at 55�C, and was totally inactivated at 70°C. Thermal stability of the enzyme was not enhanced by NAD+ or ethanol. The substrate specificity of the enzyme is reported. Cysteine and mercaptoethanol activated the enzyme, whilep-chloromercuribenzoate, Cu2+, Hg2+, B4O72- -, Zn2+ and EDTA inhibited it. The influence of ethanol, acetaldehyde and growth substances on alcohol dehydrogenase activity in germinating broad bean seeds and plant tissues was also studied.

scholarly journals PARTIAL CHARACTERIZATION of lipase from COCOA BEANS (Theobroma cacao. L.) of clone PBC 159

2010 ◽  
Vol 8 (3) ◽  
pp. 448-453
Author(s):  
Ratna Agung Samsumaharto
Keyword(s):  
Theobroma Cacao ◽  
Cocoa Bean ◽  
Cocoa Beans ◽  
Ph Optimum ◽  
Nitrobenzoic Acid ◽  
Lipase Enzyme ◽  
Wide Range ◽  
Km Value ◽  
Theobroma Cacao L

A study was carried out to characterize the cocoa lipase from cocoa beans (Theobroma cacao, L.) of clone PBC 159. The optimum temperature of cocoa lipase was 30-40 °C and the pH optimum was 7.0-8.0. The moleculer weight of the lipase enzyme was in between 45-66 kDa. The results indicate that Km value for cocoa bean lipase was 2.63 mM, when trimyristin was used as a substrate. The incubation of cocoa bean lipase with triolein and tributyrin (as substrate) yielded Km of 11.24 and 35.71 mM, respectively. The Vmax value obtained from the incubation of the lipase with a wide range of substrates, including tributyrin, trimyristin and triolein, are expressed as µmole acid/min/mg protein for cocoa lipase. Vmax values decreased with the increase in the triacylglycerol chain-length, with Vmax values of 27.78, 13.16 and 11.63 µmole acid/min/mg protein when incubated with tributyrin, trimyristin and triolein, respectively. Inhibition of lipase occurred in the presence of diisopropyl flourophosphate, N-bromosuccinimide and 5,5-dithiobis-(-2-nitrobenzoic acid).   Keywords: characterization, lipase, cocoa beans

scholarly journals Isolation, Purification, and Characterization of Fungal Laccase from Pleurotus sp.

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Sunil S. More ◽  
Renuka P. S. ◽  
Pruthvi K. ◽  
Swetha M. ◽  
S. Malini ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Laccase Activity ◽  
Gel Filtration ◽  
Industrial Enzymes ◽  
Purification And Characterization ◽  
Sds Page ◽  
Concomitant Reduction ◽  
The One ◽  
Inhibited Enzyme

Laccases are blue copper oxidases (E.C. 1.10.3.2 benzenediol: oxygen oxidoreductase) that catalyze the one-electron oxidation of phenolics, aromatic amines, and other electron-rich substrates with the concomitant reduction of O2 to H2O. They are currently seen as highly interesting industrial enzymes because of their broad substrate specificity. A positive strain was isolated and characterized as nonspore forming Basidiomycetes Pleurotus sp. Laccase activity was determined using ABTS as substrate. Laccase was purified by ionexchange and gel filtration chromatography. The purified laccase was a monomer showed a molecular mass of 40±1 kDa as estimated by SDS-PAGE and a 72-fold purification with a 22% yield. The optimal pH and temperature were 4.5 and 65°C, respectively. The Km and Vmax⁡ values are 250 (mM) and 0.33 (μmol/min), respectively, for ABTS as substrate. Metal ions like CuSO4, BaCl2, MgCl2, FeCl2, ZnCl2 have no effect on purified laccase whereas HgCl2 and MnCl2 moderately decrease enzyme activity. SDS and sodium azide inhibited enzyme activity, whereas Urea, PCMB, DTT, and mercaptoethanol have no effect on enzyme activity. The isolated laccase can be used in development of biosensor for detecting the phenolic compounds from the effluents of paper industries.

scholarly journals Purification and some properties of 1-aspartamido-β-N-acetylglucosamine amidohydrolase from human liver

1977 ◽  
Vol 165 (3) ◽  
pp. 497-502 ◽  
Author(s):  
B Dugal ◽  
J Strømme
Keyword(s):  
Enzyme Activity ◽  
Human Liver ◽  
Disc Electrophoresis ◽  
Temperature Dependent ◽  
Ph Optimum ◽  
Total Enzyme Activity ◽  
Bivalent Ions ◽  
Apparent Homogeneity ◽  
Km Value ◽  
Total Enzyme

Human liver 1-aspartamido-beta-N-acetylglucosamine amidohydrolase (aspartylglucosylaminase, EC 3.5.1.26) was purified 17 500-fold to apparent homogeneity as judged from polyacrylamide-gel disc electrophoresis. A pH optimum of 7.7-9.0 was found. The Km value was pH- and temperature-dependent. At 37 degrees C and pH 7.7, Km was 0.16 mM and it increased to 0.29 at pH 6.0 and 0.23 at pH 9.0. At 25 degrees C and pH 7.7, a Km value of 0.99 mM was obtained. When the substrate concentration was varied, apparent Michaelis-Menten kinetics were obtained. p-Hydroxymercuribenzoate, glutathione or cysteine had no effect on the enzyme activity; 5 mM-N-acetylcysteine inhibited about 47% of the total enzyme activity. Apart from Cu2+, other bivalent ions were virtually ineffective at 1 mM. The kinetic study differentiates this enzyme from aspartylglucosylaminase from other sources.

scholarly journals Characterization of a high-affinity membrane-associated ornithine decarboxylase from the free-living nematode Caenorhabditis elegans

1990 ◽  
Vol 270 (3) ◽  
pp. 599-604 ◽  
Author(s):  
J M Schaeffer ◽  
M R Donatelli
Keyword(s):  
Enzyme Activity ◽  
Caenorhabditis Elegans ◽  
Ornithine Decarboxylase ◽  
Decarboxylase Activity ◽  
Nematode Caenorhabditis Elegans ◽  
Free Living ◽  
Affinity Membrane ◽  
Free Living Nematode ◽  
Km Value

Ornithine decarboxylase has been identified and characterized in the free-living nematode Caenorhabditis elegans. Unlike previously described ornithine decarboxylases, the enzyme activity is membrane-associated and remains in the membrane fraction after treatment with high salt, detergents or phosphatidylinositol-specific phospholipase C. Ornithine has an apparent Km value of 2.7 microM for ornithine decarboxylase. The enzyme is competitively inhibited by arginine and lysine with Ki values of 4.0 and 24.4 microM respectively. None of the other naturally occurring amino acids inhibited more than 10% of the enzyme activity at concentrations up to 1 mM. Agmatine, putrescine, spermidine and spermine inhibit ornithine decarboxylase in a non-competitive manner with Ki values of 10, 53.5, 59 and 855 microM respectively. A similar ornithine decarboxylase activity was also identified in membrane preparations from the parasitic nematode Haemonchus contortus.

Isolation and Characterization of Rice Prolamin

2011 ◽  
Vol 365 ◽  
pp. 187-193
Author(s):  
Xin Xin Song ◽  
Xian Ming Zhao ◽  
Ya Nan Li ◽  
Xue Peng ◽  
Shu Hong Sun ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Rice Flour ◽  
Extraction Condition ◽  
Yield Efficiency ◽  
Isolation And Characterization ◽  
Sds Page ◽  
Optimum Extraction ◽  
Optimum Extraction Condition

Rice prolamin, constituting 10, 13 and 16 kDa polypeptides, is indigestible and may work as a kind of ‘resistant protein’. To investigate the effective method for isolation of prolamin, in this study, prolamin fractions were extracted from defatted rice flour by 70% ethanol, 55% and 60% n-propanol, 55%, 60% and 100% ethylene glycol, and 60% isopropanol, respectively. The isolated prolamin fractions were compared and characterized by yield, efficiency of extraction and SDS-PAGE patterns. Our results indicated that the optimum extraction condition for isolation of prolamin was 55% n-propanol, with 13 kDa and 16 kDa as the dominant fractions in prolamin.

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